(3) We do not find any other place in the whole Torah except here where G’d commands us to “bless” His name. This is the verse which prompted David to say in Psalms 145,1 “and I will bless Your Name.” He also said הודו לו ברכו שמו, “give thanks to Him, bless His Name” (Psalms 100,4). We find many similar quotes in the Book of Psalms.

It is a mitzvah for everyone to study Torah at the table.

One should be exceedingly careful to say דברי תורה, words of Torah, at the table. For any table at which דברי תורה, words of Torah, are not said, it is considered as if they ate from the offerings of the dead.

(2)"from the offerings of the dead": [This means] the sacrifices of idol worship, as it is written (Psalms 106:28), "And they became attached to Baal Peor and they ate from the offerings of the dead."

(1)Rabbi Shimon says: Three who ate at one table and did not say upon it words of Torah - it is as if they ate from the offerings of the dead: He means to say that since they did not say words of Torah, behold all of the tables are as if they were full of offering to idolatry which is considered to be like feces. Since the gathering of three people is called a group, as [indicated by the fact that] they would have an invitation (mezamnin) for the Grace after the meals. And one should not join them if there are no words of Torah among them, as that is removing the yoke of Torah. They are eating and drinking and enjoying, [but] the mention of Torah does not arise upon their hearts - woe to them and woe to their enjoyment.

(1) Idolatrous sacrifices are called the offerings of the dead, as the verse (Psalms 106:28) called it, as we explained in the third chapter of Idol Worship (Rambam Mishnah Avodah Zarah 3:8). And Yishayahu also called it "vomit and feces" to disgrace it, [just] like idolatry itself is called dung and abominations. And before this verse is a verse that indicates occupation with food and drink and ignoring Torah and its study, and because of this the tables are all as if they ate upon them dirty things and feces - meaning to say, idolatry. And that [verse] is his saying before this verse, "But these are also muddled by wine and misled by ale" (Isaiah 28:7).

One should study Mishnah, Halachah, Aggadah or Mussar. One does not fulfill his obligation to study Torah at the table by making the blessings after the meal and consequently he should at least say some Tehillim, preferably "מִזְמוֹר לְדָוִד יקוק רֹעִי לֹא אֶחְסָר" after hamotzi, which qualifies as words of Torah and is also a prayer sustenance.

It's also good to say [the mizmor of מִזְמוֹר לְדָוִד יקוק רֹעִי לֹא אֶחְסָר] before eating... One who says it will not be lacking inparnassah and it's also good and beneficial for the soul.

One should say a halacha before mayim acharonim. There are times that one may rely on this halacha in place of saying דברי תורה, words of Torah, at the table before [reciting] Birkas Hamazon. When one has no time at all to say דברי תורה, words of Torah, some say that he may say a halacha from the Oral Torah.

וְאָכַלְתָּ לִפְנֵי יקוק' אֱלֹקֶיךָ, you shall eat before Hashem, your G-d, includes speaking words of Torah, since the Holy One, blessed be He is in front of him. By doing this, one fulfills זֶה הַשֻּׁלְחָן אֲשֶׁר לִפְנֵי יקוק, this is the Table that is before Hashem, and וְאָכַלְתָּ שָּׁם לִפְנֵי יקוק אֱלֹקֶיךְ, you shall eat it there before Hashem, your G-d.

If one thinks in mishnayos during the time that he’s eating the seudah, how good and how pleasant it is! You’re eating and drinking is like eating and drinking from korbanos and nesachim before Hashem.

(3) Do not remove the tablecloth or bread until after Birkas Hamazon. Bread should be on the table at the time of Birkas Hamazon to demonstrate the abundance of goodness from Hashem, blessed be His Name—that He gives us enough to eat and to spare, as Elisha [the prophet] said to his servant: "For so said Hashem, eat and leave over." Another reason for this custom is that Hashem's blessing has no effect on a void. It is only effective on some existing substance, as Elisha said to the wife of Ovadiah: "What do you have in the house?" [which I can bless.]

Hashem’s blessing does not settle on something empty, but only operates when there is something there, as was the case with the oil flask of Elisha.

Whoever does not leave over bread on his table will not see a sign of blessing.

Although it is permissible to throw away crumbs smaller than a kezayis, doing so can cause poverty.

There is a custom to cover knives during Birkas Ha’Mazon but not on Shabbos or Yom Tov.

Ironshortens the life of man and, therefore, it is not right that it should be lying on the table, since a table is compared to an altar, which serves to extend the life of man. That is why it is statedwith respect to the stones from which the altar is built: “You should not raise iron over them”. Once when someone reached the blessing ובנה ירושלים, who builds Yerushalayim, he remembered the destruction of the Beis HaMikdash and in his distress inserted a knife in his belly.

Yaakov’s blessing ומשמני הארץ, fat of the earth, so we cover the knife, which is Eisav’s blessing ועל־חרבך תחיה, by your sword you shall live. The hint that the Angel of Death’s sword has no power over one who bentches with concentration.

Mayim Achronim (washing after a meal) is mandatory

Rav Ḥiyya bar Ashi said: For what reason did the Sages say that the final waters are an obligation? It is due to the fact that there is the presence of Sodomite salt, which blinds the eyes even in a small amount. Since Sodomite salt could remain on one’s hands, one must wash them after eating. This obligation is binding even in a camp because soldiers are also obligated to maintain their health.

§ The baraita further teaches that final waters are an obligation. Rav Yehuda, son of Rabbi Ḥiyya, says: For what reason did the Sages say that final waters are an obligation? It is because Sodomite salt is sometimes present, a small amount of which blinds the eyes. Since Sodomite salt could remain on one’s hands, one must wash them after eating. Abaye said: And this type of dangerous salt is present in the proportion of a pinch [korta] in an entire kor of regular salt. Rav Aḥa, son of Rava, said to Rav Ashi: If one measured salt between meals, what is the halakha? Must he wash his hands afterward? He said to him: It is not necessary to say this; he is certainly obligated to do so.

AND YOU SHALL BE HOLY, THESE ARE THE FINAL WATERS.We who do not have S’dom salt available in our hands and we therefore we do not regularly wash our hands after the meal, the lack of washing does not prevent us from reciting birchas hamozon.
However, fastidious people who regularly wash their hands after the meal, for them, not washing one’s hands definitely prevents them from reciting birchas hamozon and they must wash their hands before birchas hamozon.

The opinion of theGra in his Bi’ur is that one must wash his hands after the meal nowadays as well… TheMagein Avraham writes, likewise, citing the kabbalists, that everyone should be careful to wash his hands after the meal. The Maharshal is also stringent about this in his work Yam Shel Shelomoh...

This is a matter of holiness and whoever treats matters of holiness lightly, his days and years will be shortened.

One must wash at least until the joints at the ends of the first two sections of the fingers.

Some people are careful to wash mayim acharonim but only put a few drops of water on their fingertips, not even enough to reach the first knuckles. Some just simply touch the water, their fingers remaining just as dirty from the food as they were before. This is unfortunate and does not fill the obligation whatsoever. One must wash at least until the second knuckles.

(2) Do not wash on ground where people walk, because a damaging spirit dwells on this water...

[1] It is best to take away/ cover the water before bentching

There is a question of danger involved if a person passes over water with which someone has washed his hands after the meal.

(2) Rather wash into a vessel or under the table, dry your hands and then recite Birkas Hamazon.

The Rambam is of the opinion that washing the hands without drying them is not classed halachically as washing them. One may be lenient about this. Nevertheless, initially, it is desirable to dry one’s hands in order to act in a way which satisfies all opinions.

He must also be careful not to make an interruption in between the washing of his hands for after the meal and the blessings for after the meal, not even of words of Torah.

One should wash into a vessel (or sink – יבי"א) but not onto the ground as the ruach rah on the water can harm someone walking over it.

(7) I have observed that the general populace has become lax about this mitzvah, by which they incur mortal guilt for transgressing the words of our Sages. For the importance of this mitzvah is indicated clearly in a passage in [the Gemara] Eruvin (17b): Abaye said: All who go out to fight in an obligatory war, as well as those engaged in the performance of a mitzvah are exempt from washing the hands... but the last waters (the hand-washing following the meal) is obligatory.

(8) According to the Zohar and other Kabbalistic works there is a deep esoteric reason why the hand-washing after the meal is more obligatory than the one before the meal...

The majority of the blessings that the Sages, ordained, they instituted that they should be recited over a cup of wine. The reason is because by reciting the praise and the blessing for Him, over a glass, one thereby honors and offers suitable praise to the Holy One, blessed be He.

Rabbi Yoḥanan said: Anyone who recites a blessing over a full cup, they give him a boundless inheritance... Rabbi Yosei bar Ḥanina says: He merits and inherits two worlds, this world and the World-to-Come.

(1) Some authorities hold that even an individual reciting Birkas Hamazon should do so over a cup.

He should not eat without trying to get wine first if possible...

Others say only three or more people must; yet others say although it is a great mitzvah and praiseworthy to do so, even three do not need to.

The Mechaber does not rule on the matter... and people do not generally try to find wine if there is none readily available. However, if one has a zimun and there is wine available (Especially if it is on the table - רוח חיים), according to all opinions it is definitely praiseworthy to do so.

However, the Zohar and Arizal side with the second opinion, giving mystical reasons for it. However, an individual should not

The cup of blessing for the Birkat HaMazon requires washing on the inside and rinsing on the outside. And if it was clean without residue on the cups, the rinsing and washing are not necessary.

Although wine is not indispensable for Grace after meals, still if it is said with wine, according to the custom mentioned, it is necessary that the cup used for Grace should first be washed within and rinsed without, and then filled with pure wine. When the second blessing—that for the holy land is reached, a little water is poured into the cup so that the contents may be pleasant to drink. After the Cup for Grace is on the table, there must be no conversation. But all remain silent till the Grace after meals and the blessing for the wine have been said, and then they drink.

The kos must be totally clean. If it was drunk from or otherwise got dirty, it must be washed inside and out (SA 183:1). Be-di’avad, if it is difficult to wash the kos, one may wipe it out and clean it using a napkin (MB ad loc. 1).

The cup for blessing should be filled up to the rim.

One needs to seek out a full cup [of wine] [for blessing over the Birkat HaMazon]

One receives the cup of blessing with two hands, and, when one begins blessing, one should lift it up with one's right hand without assisting it with one's left hand... And one should elevate it a fistbreadth from the ground if one was sitting on the ground. And if one was lounging at a table, one elevates it above the table a fistbreadth. And one sets one's eyes upon it, so as not to lose mindfulness about it.

After he drinks, he should pass it to his wife, family and guests so that they also get a blessing.

GEMARA: With regard to the basic mitzva of zimmun, the Gemara asks: From where are these matters derived, that after a meal in which three diners participated, a zimmun must be recited? Rav Asi said: As the verse states: “Praise God with me, and we will exalt His name together” (Psalms 34:4), i.e., the one reciting the blessing turns to at least two others to praise God together. Rabbi Abbahu said: The source of the mitzva of zimmun is derived from the verse here: “When I call the Name of the Lord, give [plural] praise to our God” (Deuteronomy 32:3).

Some hold that zimun is derabanan while others hold it is min HaTorah.

One should put in a lot of effort [to recite Birkas HaMazon] with a zimun. This has tremendous power to eliminate and drive away the sitra achra.

It is an even bigger mitzvah to try to find ten people to make him a zimun with Hashem’s Name.

When two people eat together, even though one may recite the beracha of hamotzi for the other, it is a mitzvah for each one to recite birkas hamazon for himself. This is true when both of them know how to recite birkas hamazon. If one knows and the other doesn’t the one who knows how should recite the beracha and the other will fulfill his obligation assuming he understands lashon kodesh but doesn’t know how to recite birkas hamazon. He must listen to each word that is recited....Rama: The one reciting the beracha must have in mind to discharge his friend’s obligation. Mechaber: If he does not understand he does not fulfill his obligation by listening. When three people eat together they may not separate and when two people eat together it is a mitzvah for them to search for a third to join their zimun. When four or five people eat together they may not separate since they are all obligated to make a zimuun. When the group is comprised of six they may separate since each group will make its own zimun and this is true until the group reaches ten. Once the group contains between ten and twenty people they may not separate until there are twenty since they will mention Hashem’s Name

(2) When you recite a berachah your mouth should be free of saliva nor should anything else be in your mouth, as it is said: "My mouth shall be full of Your praises."

One should make sure to be excused before bentching, so as to appear presentable before Hashem.

A G-d fearing person should make an effort to dress himself with an outer garment and a respectable head covering.

One must sit while bentching in order to focus properly. One should not lean, which is arrogant; he should sit with awe.

There is a special requirement for Birkas Hamazon to be said pleasantly, in a loud voice and joyfully.

One who does so will be showered with blessing.

[When reading the Shema,] one must hear with their ears what comes out of their mouth, but if one did not hear it, they [still] fulfilled their obligation as long as they brough it out of their lips (ie. articulated it with their mouth).

It is desirable to say the blessings in a loud voice always, since blessing aloud inspires one to bless from the heart.

One should concentrate in blessings of the meaning of the words...

(1) Before reciting a berachah you must be sure which berachah you are required to recite, so that when you mention Hashem's Name which is the principle part of the berachah, you will know how to conclude the berachah. It is forbidden to do anything else while reciting a berachah. Do not recite the berachah hurriedly but think of the meaning of the words... You should not recite the berachah automatically, out of habit, spouting words from your mouth without thinking of their meaning.

The four blessings of Birkas Hamazon have similar laws like the tefillah of Shemoneh Esrei.

The poskim imply that although the fourth blessing is a rabbinic law, Chazal were strict so that it would not be degraded.

One cannot interrupt even to answer to Kaddish, Kedushah or Berichu...

The only difference is that we stand for Shemoneh Esrei and sit for Birkas Hamazon...

It is forbidden​​​​​​​ for one may not do activity while Birkas Hamazon.

On account of our many sins, ignorant people cheapen Birkas Hamazon by saying it very fast. Some do activity, motion with their hands, mouth with their lips, play with their fingers and the like. This needs great strengthening

Abridged Book of Trembling Ones - Commandment of Moshe. The abridgment was done by the writer of the Chayei Adam. Chapter 1 - Positive commandments from the Torah which are dependent on the heart:

Included in the commandment of “fearing Hashem” is to say Hashem’s Name with awe in his heart.

One should concentrate in blessings of the meaning of the words. When mentioning the name HASHEM, concentrate on the meaning of the recital being lordship that He is the Master of all, and concentrate on the Yud-Hei that Was, Is, and Will Be. And when one mentions ELOHIM, concentrate on that He is Strength, Master of Wherewithal and Master of the powers of all.

Rebbe Yodai: Great is the power of Birkas Hamazon (with concentration – יפה ללב), which adds blessing to one’s work.

There are heavenly prosecutors who try to prevent a person from getting his sustenance. When he bentches with concentration, the berachos act as his defendants and Hashem pours blessing down onto him.

I have received as a tradition from my teachers, may God protect them, that any one who is careful about Grace after Meals will have his food available with dignity all of his days. [These] and the rest of its details are elucidated in Tractate Berakhot (see Tur, Orach Chaim 188).

(7) One who does recite it with devotion, on the other hand, will merit hearing it recited by King Dovid, peace be upon him, when the Holy One Blessed is He makes a feast for the righteous in the time to come (Pesachim 119b).

Af, Shetzef, Ketzef and the Angel of Death All have no power over someone who recites Birkas HaMazon with concentration.

It is fitting for every person who has fear of Heaven to be anguished and concerned regarding the destruction of the Temple.

(11) The destruction of the Temple - The Shl"a wrote that at every meal, one should recite "Al naharot Bavel" ("By the Rivers of Babylon..." - Psalms 137:1). And on Shabbat, and also on days that Tachanun is not said, one should say "Shir Hama'alot b'shuv Hashem..." ("A song of ascents. When the Lord returns..." - Psalms 126:1). And the main thing is to know/understand what one is saying, and to have concentration.

One who luxuriates at his table and delights in those foods ought to call to mind and to feel concern for the holiness of the Holy Land and for the Temple of the King that has been destroyed. In consideration of the sadness that one feels at one's table--in the midst of the joy and celebration [lit. drinking] there--the Holy Blessed One accounts it to one as if one has rebuilt His House and rebuilt all the ruins of the Temple. Happy is one's portion!

The purpose of a zimun is to give honor to Hashem by gathering together and inviting each other to bless His Great Name.

With regard to the origins of the four blessings of Grace after Meals, Rav Naḥman said:Moses instituted for Israel the first blessing of: Who feeds all, when the manna descended for them and they needed to thank God.

Before reciting bentching, one should prepare himself to fulfill the Torah Commandment of Birkas HaMazon with awe, love, intense concentration, great joy, and gladness... he should close his eyes and clasped his hands, right over left, as one would sit before the King of the world (see also Siddur HaRashash Nekudos HaKosef – Cheilek Kavanahs HaShulchan D’Shabbos Kodesh by Yechezkel Bing, page 298).

(3)You should fear and tremble when you mention the Name of Hashem, Blessed Be His Name...​​​​​​​

With regard to the origins of the four blessings of Grace after Meals, Rav Naḥman said...Joshua instituted the blessing of the land when they entered Eretz Yisrael.

With regard to the formula of Grace after Meals, the Gemara continues: It was taught in a baraita: Rabbi Eliezer says: Anyone who did not say: A desirable, good, and spacious land in the blessing of the land, and who did not mention the royal house of David in the blessing: Who builds Jerusalem, did not fulfill his obligation...

He must make mention of the covenant of circumcision preceding mention of the Torah, as this, the Torah, was given to the Jewish people with three covenants.

Rabbi Abba says: One must mention thanks in the blessing of thanksgiving in Grace after Meals at the beginning and the end of the blessing.

With regard to the origins of the four blessings of Grace after Meals, Rav Naḥman said... David and Solomon instituted the third blessing: Who builds Jerusalem...

Have compassion, Adonoy, our God, on Israel, Your people, on Jerusalem, Your city, on Zion, the dwelling place of Your glory, on the kingship of the house of David, Your anointed; and on the great and holy House upon which Your Name is called. Our God, our Father tend us, nourish us, maintain us, sustain us, relieve us and grant us relief Adonoy, our God, speedily from all our troubles. Adonoy, our God—may we never be in need of the gifts of men nor of their loans, but only of Your hand which is full, open, holy and generous, so that we may not be shamed nor humiliated forever and ever.

Rebuild Jerusalem, city of the Holy Sanctuary, speedily, in our days. Blessed are You, Adonoy, Builder of Jerusalem in His mercy. Amein.

Rav Naḥman said...They instituted the blessing: Who is good and does good, at Yavne in reference to the slain Jews of the city of Beitar at the culmination of the bar Kokheva rebellion. They were ultimately brought to burial after a period during which Hadrian refused to permit their burial. As Rav Mattana said: On the same day that the slain of Beitar were brought to burial, they instituted the blessing: Who is good and does good, at Yavne. Who is good, thanking God that the corpses did not decompose while awaiting burial, and does good, thanking God that they were ultimately brought to burial.

There are deep, Kabbalistic meanings of each word of this brachah, and if one rushes through and misses or swallows a word, he loses out on much goodness.

Blessed are You, Adonoy our God, King of the Universe, the Almighty, our Father, our King, our Mighty One, our Creator, our Redeemer, our Maker, our Holy One, Holy One of Jacob, our Shepherd, Shepherd of Israel, the King, Who is good and beneficent to all. Every single day He has done good, does good, and will do good to us. He has rewarded us, He rewards us, He will reward us forever with favor, kindness, and compassion, relief, rescue, and success, blessing, deliverance, and consolation, maintenance, sustenance, compassion, life, peace, and everything good; and of all good things may He never deprive us.

Ever since we lost the Jewish kingdom and our Beis Hamikdash, we have lacked so much good. It is as if we went from life to death. However, when Hashem redeems us, we will return back to life. Any Jewish heart should break just thinking about this.

Rav Chayim of Volozhin of blessed memory wrote in the Gate of Divine Spirit on page 9b the following:

My master of blessed memory said to me that one's main ability to attain Ruach Hakodesh depends upon his focus in all his berachos.

WHO CREATES THE MANY FORMS OF LIFE AND THEIR NEEDS FOR ALL THAT YOU HAVE CREATED. Tosfos will teach us the meaning of this b’rochoh which is recited so often. וחסרונם and that which they lack, refers to necessities such as bread and water, without which it is impossible to survive.
After thanking Hashem for the necessities we add: Together with all that he created to give life through them for all the living. This means that Hashem created the necessities together with all else that there is in this world, that even if he had not created them the world would still be able to live without them. For he created them only for mere enjoyment such as apples and similar foods. And we conclude this b’rochoh with, blessed is the source of life of the worlds. And in Yerushalmee the conclusion is blessed are you Hashem the source of life of the worlds.

The difference in blessings between tree fruit and fruit of the earth and something which does not originate from the earth, is specific to the prior blessing. but the after blessing is the same for all of these and it is: Baruch ata Hashem Eloheinu melech ha'olam boreh nefashot rabot v'chesronan al kol mah shehbara l'hachayot bahen nefesh kol chai baruch ata hashem chai haolamim. therefore if one at tree fruit that is not from the seven species and fruit of the earth, because the after blessing is the same for them, one makes one blessing on both. the meaning of the blessing is: who makes many beings and everything they are missing and on all other things that he created in the world that had God not created them they would not be missing from them [the beings], for they are only meant for pleasure, to imbue life of every being. and there are those who say "boreh nefashot rabot v'chesronan al kol mah shebarata l'hachayot bahem nefesh kol chai". and in our gemara it does not mention a conclusion for her [this blessing], but in the Jerusalem [Talmud] it concludes the blessing "baruch ata hashem chey ha'olamim" and this was the custom of my master my father, the Rosh, may his memory be a blessing.