If your brother becomes impoverished and his hand falters in your proximity, you shall strengthen the stranger and the citizen to live with you. (25:35)
This is referring to the mitzvah of Tzedakah (charity) as we see in Sefer HaChinuch (a work written in 13th-century Spain that clearly details the 613 commandments and explains the reasons behind them) in Mitzvah 479:
The commandment of charity (tzedekah): To do charity with the one who needs it, with happiness and out of the goodness of one’s heart; meaning to say, that we give from our money to one who is lacking, and to strengthen the poor in all areas that he needs for his sustenance, with all of our ability. And about this is it stated (Deuteronomy 15:8), “you shall surely open your hand to him.” […] And it is also stated (in the verse we cited above, Leviticus 25:35), “and you shall strengthen the stranger and the citizen to live with you.”
Regarding giving tzedakah, Pirkei Avot (Chapters of the Fathers, 5:13) states:
There are four types of charity givers. He who wishes to give, but that others should not give: his eye is evil (i.e. he is begrudging) to that which belongs to others; he who wishes that others should give, but that he himself should not give: his eye is evil towards that which is his own; he who desires that he himself should give, and that others should give: he is a pious man; he who desires that he himself should not give and that others too should not give: he is a wicked man.
The first of the four givers mentioned above is one who wishes to give, but that others do not give. We say that he has an evil eye to that which belongs to others. How does his desire that others not give tzedakah portray an evil eye towards that which belongs to those people? R’ Ovadiah of Bartenura, Italy (c. 1445-c.1515) writes in his commentary to this Mishnah that it is known that giving charity makes one prosperous. If he doesn’t want others to give, that means he doesn’t want that for them. That’s the evil eye to that which belongs to others.
The commentary on Pirkei Avot called Midrash Shmuel asks that the phrase, “his eye is evil towards,” is always used in the context of something that is already present and means to say that the person begrudges someone of what they have. But here the reward for the tzedaka is not yet here since the whole point is that this person doesn’t want others to give tzedaka so that they won’t receive reward for that. Moreover, there are times when Hashem withholds reward for a mitzvah as a test for a person so that they will grow spiritually and the reward is reserved for the Afterlife. How then does this phrase of, “his eye is evil towards,” belong here?
Midrash Shmuel answers that by other mitzvos the reward may be delayed in order to test a person. But by Tzedaka the roles are reversed.
הָבִיאוּ אֶת־כָּל־הַמַּעֲשֵׂר אֶל־בֵּית הָאוֹצָר וִיהִי טֶרֶף בְּבֵיתִי וּבְחָנוּנִי נָא בָּזֹאת אָמַר ד’ צְבָקוֹת אִם־לֹא אֶפְתַּח לָכֶם אֵת אֲרֻבּוֹת הַשָּׁמַיִם וַהֲרִיקֹתִי לָכֶם בְּרָכָה עַד־בְּלִי־דָי׃
Bring the full tithe into the storehouse, and let there be food in My House, and thus put Me to the test—said the LORD of Hosts. I will surely open the floodgates of the sky for you and pour down blessings on you. (Malachi 3:10)
Hashem tells us to test Him about the reward for giving to others! That means the reward for giving tzedakah is guaranteed and we can consider it as if we already have it! Therefore the Mishna can use the phrase “his eye is evil towards.”
Accordingly, giving tzedakah is not just giving away your money. It’s actually the best investment you can make. Profits are guaranteed!
Shabbat Shalom!
Yitzchak