Halachic and Spiritual Underpinnings of Sefiras HaOmer - How many Mitzvos is Sefiras HaOmer?

(15) And from the day on which you bring the sheaf of elevation offering—the day after the sabbath—you shall count off seven weeks. They must be complete: (16) you must count until the day after the seventh week—fifty days; then you shall bring an offering of new grain to the LORD.

(9) You shall count off seven weeks; start to count the seven weeks when the sickle is first put to the standing grain. (10) Then you shall observe the Feast of Weeks for the LORD your God, offering your freewill contribution according as the LORD your God has blessed you.

(5) and instructed them as follows, “Thus shall you say, ‘To my lord Esau, thus says your servant Jacob: I stayed with Laban and remained until now;

(5) The following religious acts may be done during the whole of the day [on which they are obligatory], viz.:—The reading of the Megillah; of the Hallel; the sounding of the cornet; the use of the loolab, or palm-branch; the prayer at the additional offering; the additional offering; the confession of sin on sacrificing the bulls; the confession to be made on bringing the [second] tithe; the confession of sin by the high priest on the day of atonement; the imposition of hands [on a sacrifice]; the slaughtering of a sacrifice; the waving of the offering; the bringing it to the altar; the taking of the handful of flour (Lev. 2:2); the burning with incense of the fat of a sacrifice on the altar; the pinching or wringing off the head of fowls brought as sacrifices (Lev. 1:15); the receiving of the blood of a sacrifice; the sprinkling thereof on the altar; the giving the bitter waters to drink to a woman suspected of adultery; the striking off of the heifer's neck (Deut. 21:4); and the purification of a leprous person.

(6) The following acts may be done during the whole of the night: the cutting of the sheaves for the "omer", and the burning with incense of the fat and members of a burnt-offering on the altar (Lev. 6:9). This is the rule:—Whatever is commanded to be done by day, may legally be done during the whole of the day; and whatever is commanded to be done by night, it is lawful to do during the whole of the night.

(1) The commandment of counting the omer: To count forty-nine days from the bringing of the omer which is on the sixteenth day of Nissan, as it is stated (Leviticus 23:15), "And you shall count for yourselves from the morrow of the Shabbat from the day of your bringing the omer of waving." And this tallying is an obligation, and it is upon us to count the days on each day and, likewise, the weeks. As Scripture said to count fifty days and also said (Deuteronomy 16:9), "Seven weeks shall you count for yourself." And in explanation, Abbaye said in the Gemara in Menachot 66a, "It is a commandment to tally the days and it is a commandment to tally the weeks" (see Sefer HaMitzvot LaRambam, Mitzvot Ase 161). And there are some of the commentators (see the end of Ran on Pesachim) the opinion of which is that the intention of the verse is to tally the weeks specifically when they are full, but there is no need to mention [them] every day and say that they are such and such days and such and such weeks. And there are some that say (Rosh in his Responsa 24:13) that the [proper] way is to mention the tally of weeks with the days always on every day. And one who fears the Heavens will choose their way to remove [himself] from any doubt, and not be concerned about the elegance of the words. And so have they practiced today in all places of which we have heard.

(2) And Rambam, may his memory be blessed, wrote (Sefer HaMitzvot LaRambam, Mitzvot Ase 161), "And do not be misled by their, may their memory be blessed, saying [that] it is a commandment to tally days and it is a commandment to tally weeks, and think that they are two commandments. As the intention of this is not to say that it be a commandment on its own, but [rather] it is a part of the [different] parts of the commandment. However, it would have been two commandments had they said, 'The tally of the days is a commandment and the tally of the weeks is a commandment.' And this is what will not be hidden from one who is exact in the thing and elucidates it - that when you say, 'It is obligated that he do such and such,' it is not obligatory from this statement that this matter be a commandment on its own. And the proof that elucidates this is our tallying the weeks as well on each night, in our saying that they are such and such weeks and such and such days. And if the weeks were a commandment on their own, their tally would have only been arranged on the nights of the [ends of] the weeks alone. And they would have had two blessings: 'and commanded us about the counting of the days of the omer'; and 'about the counting of the weeks of the omer' - but the matter is not like this. [Rather] the commandment of the counting of the omer is its days and its weeks, as we have written." To here [are his words].

(5) From the laws of the commandment is that which they, may their memory be blessed, said (Menachot 66a) that it is a commandment to tally them from the evening so that they be complete. As the verse stated, "complete shall they be" - and they, may their memory be blessed, said, "From when are they complete? From when he begins from the evening." And nonetheless, the commentators (Tosafot in the name of Behag on Menachot, s.v. zecher) explained that if he forgot and did not tally from the evening, he [may] tally on the morrow the whole day. And some say there that one who forgot and did not tally one day may not tally again that year, since they are all one commandment; and since he forgot one day from them, the entire count is negated for him. And our teacher in our generation did not concede to this reasoning. Rather, one who forgot a day should say, "Yesterday was such," without a blessing; and tally the other [days] with all of Israel. [...].