The Rambam, Tur, and Maran Ha’Shulchan Aruch write that the amount one should donate for Tzedakah is, if one can afford it, based on the necessities of the needy people. This means that if one is extremely wealthy and can provide for the needs of poor people in one’s city, one should indeed donate whatever they lack. If one cannot afford this, the most preferable way to perform this Mitzvah is to donate up to one-fifth of one’s money to Tzedakah. However, if one gives a tenth of what one has, this is considered a “middle” level (although not as good as one who gives up to a fifth). Many great and righteous people indeed have the custom to give “a tithe of their money” by donating one-tenth of all of their profits to Tzedakah. If one donates less than a tenth to Tzedakah, one is considered by our Sages to have “a bad eye,” for one only gives others a small amount of his money (i.e. stingy).
The level of giving a fifth is the highest of all and is derived from a verse in the Torah. Indeed, the Tur writes that it is a known and tested fact that one does not lose money by donating Tzedakah; on the contrary, it shall bring one more wealth and honor as the verse states, “Upon beginning to bring the donation to the house of Hashem, eat, be satisfied, and leave over an abundant amount, for Hashem has blessed his nation.” Indeed, our Sages tell us (Shabbat 119a), “Take off tithes so that you shall become wealthy.”
The Gemara in Masechet Ketubot (50a) states: “Rabbi Il’a said: It was established in Usha that one should not donate more than one-fifth of one’s possessions to Tzedakah lest one become dependent on Tzedakah as a result.” Nevertheless, several Poskim write that this only applies to regular individuals; however, an especially wealthy person who wishes to may give more than a fifth of his assets to Tzedakah and he shall be blessed from above. This can be inferred from the Poskim we have quoted above who write that if one has the means, one should provide for the needs of all of the poor in his city and only afterwards did they mention the level of one giving a fifth which is the highest level. We can understand that they were originally referring to a donation of more than one-fifth which applies to an extremely wealthy individual who can provide for the needs of many.
One should not give less than the worth of one-third of a silver shekel per year, for this is the minimum amount of Tzedakah one must give as prescribed by Torah law. If one gives less than this amount, one has not fulfilled one’s obligation of donating Tzedakah. This amounts to the worth of approximately seven grams of pure silver. However, this is clearly a very low level of donating Tzedakah and would the Sages of Israel be in control, one would be forced to give as much as one could afford. Certainly, Hashem shall collect His dues from this person, for as we have said, Hashem pities the downtrodden and hears their prayers. Indeed, a Heavenly voice rings out from Har Sinai daily and cries, “Woe is to the world because of the humiliation of the Torah,” for there are countless Torah scholars who do not have enough money to even live a humble and simple lifestyle. However, if one generously donates money to Tzedakah, especially to G-d-fearing Torah scholars, one’s reward will be great indeed and all sorts of evil decrees shall be nullified for him, for Tzedakah saves from certain death. We see this from the woman from Tzefat who gave a small cake to Eliyahu Ha’Navi and because of this, her son, who was already dead, came back to life and she merited enjoying him for many more years.
There are many other fine details regarding the Mitzvah of Tzedakah and we shall, G-d-willing, address them further.