(א) חייבין אנו להזהר במצות צדקה יותר מכל מצות עשה שהצדקה סימן לצדיק זרע אברהם אבינו שנאמר כי ידעתיו למען אשר יצוה את בניו לעשות צדקה ואין כסא ישראל מתכונן ודת האמת עומדת אלא בצדקה שנאמר בצדקה תכונני ואין ישראל נגאלין אלא בצדקה שנאמר ציון במשפט תפדה ושביה בצדקה.
We are obligated to be more scrupulous in fulfilling the commandment of tzedakah than any other positive commandment because tzedakah is the sign of the righteous, the seed of Abraham our father, as it is said, “For I know him that he will command his children to do tzedakah.” The throne of Israel and the religion of truth is upheld only through tzedakah, as it is said, “In tzedakah shall you be established” (Isaiah 54:14). Israel is redeemed only through tzedakah, as it is said, “Zion shall be redeemed with judgment and those that return by tzedakah” (Isaiah 1:27)
(כב) עַשֵּׂר תְּעַשֵּׂר אֵת כָּל תְּבוּאַת זַרְעֶךָ הַיֹּצֵא הַשָּׂדֶה שָׁנָה שָׁנָה.
(22) Thou shalt surely tithe all the increase of thy seed, that which is brought forth in the field year by year.
כִּי יִהְיֶה בְךָ אֶבְיוֹן מֵאַחַד אַחֶיךָ בְּאַחַד שְׁעָרֶיךָ בְּאַרְצְךָ אֲשֶׁר יקוק אֱלֹקֶיךָ נֹתֵן לָךְ לֹא תְאַמֵּץ אֶת לְבָבְךָ וְלֹא תִקְפֹּץ אֶת יָדְךָ מֵאָחִיךָ הָאֶבְיוֹן. כִּי פָתֹחַ תִּפְתַּח אֶת יָדְךָ לוֹ וְהַעֲבֵט תַּעֲבִיטֶנּוּ דֵּי מַחְסֹרוֹ אֲשֶׁר יֶחְסַר לוֹ. הִשָּׁמֶר לְךָ פֶּן יִהְיֶה דָבָר עִם לְבָבְךָ בְלִיַּעַל לֵאמֹר קָרְבָה שְׁנַת הַשֶּׁבַע שְׁנַת הַשְּׁמִטָּה וְרָעָה עֵינְךָ בְּאָחִיךָ הָאֶבְיוֹן וְלֹא תִתֵּן לוֹ וְקָרָא עָלֶיךָ אֶל יקוק וְהָיָה בְךָ חֵטְא. נָתוֹן תִּתֵּן לוֹ וְלֹא יֵרַע לְבָבְךָ בְּתִתְּךָ לוֹ כִּי בִּגְלַל הַדָּבָר הַזֶּה יְבָרֶכְךָ יקוק אֱלֹקֶיךָ בְּכָל מַעֲשֶׂךָ וּבְכֹל מִשְׁלַח יָדֶךָ. כִּי לֹא יֶחְדַּל אֶבְיוֹן מִקֶּרֶב הָאָרֶץ עַל כֵּן אָנֹכִי מְצַוְּךָ לֵאמֹר פָּתֹחַ תִּפְתַּח אֶת יָדְךָ לְאָחִיךָ לַעֲנִיֶּךָ וּלְאֶבְיֹנְךָ בְּאַרְצֶךָ.
If there will be among you a needy person, from one of your brothers in one of your cities, in your land the Lord, your God, is giving you, you shall not harden your heart, and you shall not close your hand from your needy brother. Rather, you shall open your hand to him, and you shall lend him sufficient for his needs, which he is lacking. Beware, lest there be in your heart an unfaithful thought, saying, "The seventh year, the year of release has approached," and you will begrudge your needy brother and not give him, and he will cry out to the Lord against you, and it will be a sin to you. You shall surely give him, and your heart shall not be grieved when you give to him; for because of this thing the Lord, your God, will bless you in all your work and in all your endeavors. For there will never cease to be needy within the land. Therefore, I command you, saying, you shall surely open your hand to your brother, to your poor one, and to your needy one in your land.
(א) מִצְוַת עֲשֵׂה לִתֵּן צְדָקָה לָעֲנִיִּים כְּפִי מַה שֶּׁרָאוּי לֶעָנִי. אִם הָיְתָה יַד הַנּוֹתֵן מַשֶּׂגֶת. שֶׁנֶּאֱמַר (דברים טו-ח) "פָתֹחַ תִּפְתַּח אֶת יָדְךָ לוֹ" וְנֶאֱמַר (ויקרא כה-לה) "וְהֶחֱזַקְתָּ בּוֹ גֵּר וְתוֹשָׁב וָחַי עִמָּךְ" וְנֶאֱמַר (ויקרא כה-לו) "וְחֵי אָחִיךָ עִמָּךְ":
(ב) וְכָל הָרוֹאֶה עָנִי מְבַקֵּשׁ וְהֶעֱלִים עֵינָיו מִמֶּנּוּ וְלֹא נָתַן לוֹ צְדָקָה עָבַר בְּלֹא תַּעֲשֶׂה שֶׁנֶּאֱמַר (דברים טו-ז) "לֹא תְאַמֵּץ אֶת לְבָבְךָ וְלֹא תִקְפֹּץ אֶת יָדְךָ מֵאָחִיךָ הָאֶבְיוֹן":
(ג) לְפִי מַה שֶּׁחָסֵר הֶעָנִי אַתָּה מְצֻוֶּה לִתֵּן לוֹ. אִם אֵין לוֹ כְּסוּת מְכַסִּים אוֹתוֹ. אִם אֵין לוֹ כְּלֵי בַּיִת קוֹנִין לוֹ. אִם אֵין לוֹ אִשָּׁה מַשִּׂיאִין אוֹתוֹ. וְאִם הָיְתָה אִשָּׁה מַשִּׂיאִין אוֹתָהּ לְאִישׁ. אֲפִלּוּ הָיָה דַּרְכּוֹ שֶׁל זֶה הֶעָנִי לִרְכֹּב עַל הַסּוּס וְעֶבֶד רָץ לְפָנָיו וְהֶעֱנִי וְיָרַד מִנְּכָסָיו קוֹנִין לוֹ סוּס לִרְכֹּב עָלָיו וְעֶבֶד לָרוּץ לְפָנָיו שֶׁנֶּאֱמַר (דברים טו-ח) "דֵּי מַחְסֹרוֹ אֲשֶׁר יֶחְסַר לוֹ". וּמְצֻוֶּה אַתָּה לְהַשְׁלִים חֶסְרוֹנוֹ וְאֵין אַתָּה מְצֻוֶּה לְעַשְּׁרוֹ:
(ד) יָתוֹם שֶׁבָּא לְהַשִּׂיאוֹ אִשָּׁה. שׂוֹכְרִין לוֹ בַּיִת וּמַצִּיעִים לוֹ מִטָּה וְכָל כְּלֵי תַּשְׁמִישׁוֹ וְאַחַר כָּךְ מַשִּׂיאִין לוֹ אִשָּׁה:
(ה) בָּא הֶעָנִי וְשָׁאַל דֵּי מַחֲסוֹרוֹ וְאֵין יַד הַנּוֹתֵן מַשֶּׂגֶת נוֹתֵן לוֹ כְּפִי הַשָּׂגַת יָדוֹ וְכַמָּה עַד חֲמִישִׁית נְכָסָיו מִצְוָה מִן הַמֻּבְחָר. וְאֶחָד מֵעֲשָׂרָה בִּנְכָסָיו בֵּינוֹנִי. פָּחוֹת מִכָּאן עַיִן רָעָה. וּלְעוֹלָם לֹא יִמְנַע עַצְמוֹ מִשְּׁלִישִׁית הַשֶּׁקֶל בְּשָׁנָה. וְכָל הַנּוֹתֵן פָּחוֹת מִזֶּה לֹא קִיֵּם מִצְוָה. וַאֲפִלּוּ עָנִי הַמִּתְפַּרְנֵס מִן הַצְּדָקָה חַיָּב לִתֵּן צְדָקָה לְאַחֵר:
(ו) עָנִי שֶׁאֵין מַכִּירִין אוֹתוֹ וְאָמַר רָעֵב אֲנִי הַאֲכִילוּנִי אֵין בּוֹדְקִין אַחֲרָיו שֶׁמָּא רַמַּאי הוּא אֶלָּא מְפַרְנְסִין אוֹתוֹ מִיָּד. הָיָה עֵרוֹם וְאָמַר כַּסּוּנִי בּוֹדְקִין אַחֲרָיו שֶׁמָּא רַמַּאי הוּא. וְאִם הָיוּ מַכִּירִין אוֹתוֹ מְכַסִּין אוֹתוֹ לְפִי כְּבוֹדוֹ מִיָּד וְאֵין בּוֹדְקִין אַחֲרָיו:
(1) It is a positive commandment to give Tzedaka to poor people according to what is appropriate for the recipient if the donor can afford it as it says "You shall surely open your hand to him" and it says "And you shall strengthen the stranger and he shall live among you." And it says "and your brother shall live among you."
(2) Anyone who deliberately ignores a beggar and does not give to him commits a negative transgression as it says "Thou shalt not strengthen thy heart nor tighten thy hand against your poor brother."
(3) You are obligated to give the poor person what he lacks. If he does not have clothing, clothe him. If he does not have furniture, buy him furniture. If he is single, marry him/her off. Even if the poor person used to be extremely rich and ride a horse and have a slave to run before him, and the poor person become impoverished, buy him a horse to ride and a slave to run before him. As it says "[make up to him] his lack which he lacks." You are commanded to make up what he lacks, but not to enrich him.
(4) With regard to an orphan for whom people are seeking to find a wife for him to marry: First, we rent for him a house, provide for him a bed and all his household necessities and then we seek to find a wife for him to marry.
(5) When a poor person comes and asks for his needs to be met and the giver does not have the financial capacity, he should give him according to his financial capacity. How much? The most desirable way of performing the mitzvah is to give one fifth of one's financial resources. Giving one tenth is an ordinary measure. Giving less is stingy. A person should refrain from giving less than a third of a shekel a year. A person who gives less than this has not fulfilled the mitzvah. Even a poor person who derives his livelihood from charity is obligated to give charity to another person.
(6) If there is a poor person that you don't know , and he says "I am hungry," you should feed him without ascertaining whether he is being dishonest . Rather you should feed him immediately. If he is unclothed, and he says "clothe me," check to see if he is being dishonest. But if you know him, clothe him immediately for his dignity, without checking him.
(א) שִׁעוּר נְתִינָתָהּ, אִם יָדוֹ מַשֶּׂגֶת, יִתֵּן כְּפִי צֹרֶךְ הָעֲנִיִּים. וְאִם אֵין יָדוֹ מַשֶּׂגֶת כָּל כָּךְ, יִתֵּן עַד חֹמֶשׁ נְכָסָיו, מִצְוָה מִן הַמֻּבְחָר; וְאֶחָד מֵעֲשָׂרָה, מִדָּה בֵּינוֹנִית; פָּחוֹת מִכָּאן, עַיִן רָעָה. וְחֹמֶשׁ זֶה שֶׁאָמְרוּ, שָׁנָה רִאשׁוֹנָה מֵהַקֶּרֶן, מִכָּאן וָאֵילָךְ חֹמֶשׁ שֶׁהִרְוִיחַ בְּכָל שָׁנָה. הַגָּה: וְאַל יְבַזְבֵּז אָדָם יוֹתֵר מֵחֹמֶשׁ, שֶׁלֹּא יִצְטָרֵךְ לַבְּרִיּוֹת. (בֵּית יוֹסֵף בְּשֵׁם הַגְּמָרָא פ' נַעֲרָה שֶׁנִּתְפַּתְּתָה) וְדַוְקָא כָּל יְמֵי חַיָּיו, אֲבָל בִּשְׁעַת מוֹתוֹ יָכוֹל אָדָם לִתֵּן צְדָקָה כָּל מַה שֶּׁיִּרְצֶה (ג''ז שָׁם פ' מְצִיאַת הָאִשָּׁה וּמַיְתֵי לָהּ רִי''ף וְרֹא''שׁ וְרַ''ן וּמָרְדְּכַי). וְאֵין לַעֲשׂוֹת מִמַּעֲשֵׁר שֶׁלּוֹ דְּבַר מִצְוָה, כְּגוֹן נֵרוֹת לְבֵית הַכְּנֶסֶת אוֹ שְׁאָר דְּבַר מִצְוָה, רַק יִתְּנֶנּוּ לַעֲנִיִּים. (מהרי''ל הל' רֹאשׁ הַשָּׁנָה).
(1) The amount one should give [is as follows]. If one can afford it, he should give according to the needs of the poor. If one can not afford so much, he should give up to a fifth of his wealth - that is the best [way of performing] the mitzvah. A medium way is to give a tenth. Less than that is stingy. Giving a fifth that was referred to, means the first year from one's overall assets, and from then on giving a fifth of one's earnings annually. Note: A person should not waste more than a fifth so he should not be dependent on others. This is during his lifetime, but when he is about to pass away he can give as much charity as he wishes. A person should not use his charity to perform mitzvot such as [giving] candles to the synagogue etc., but he should give it to the poor.
אין לך דבר שעומד בפני פיקוח נפש אלא עבודה זרה וגלוי עריות ושפיכות דמים
You have no matter that stands before saving a life, other than idol worship, forbidden sexual relations, and murder.
Effective Altruism on the obligation to give
http://bostonreview.net/forum/peter-singer-logic-effective-altruism
Effective altruism is based on a very simple idea: we should do the most good we can. Obeying the usual rules about not stealing, cheating, hurting, and killing is not enough, or at least not enough for those of us who have the good fortune to live in material comfort, who can feed, house, and clothe ourselves and our families and still have money or time to spare. Living a minimally acceptable ethical life involves using a substantial part of our spare resources to make the world a better place. Living a fully ethical life involves doing the most good we can.
https://www.ted.com/talks/peter_singer_the_why_and_how_of_effective_altruism/transcript?language=en
So let's talk about effectiveness... Take, for example, providing a guide dog for a blind person. That's a good thing to do, right? Well, right, it is a good thing to do, but you have to think what else you could do with the resources. It costs about 40,000 dollars to train a guide dog and train the recipient so that the guide dog can be an effective help to a blind person. It costs somewhere between 20 and 50 dollars to cure a blind person in a developing country if they have trachoma… You could provide one guide dog for one blind American, or you could cure between 400 and 2,000 people of blindness.