Musar for Shabbat 5:10

Therefore, because of the greatness of this mitzvah, they were accustomed in all the diaspora of Israel to have societies for gemiluth chasadim to lend a man in time of need. Now, in truth, why is this holy society superior to the gemiluth chasadim that one does by himself? For several reasons: There is no comparing many doing a mitzvah to [just] a few doing it, as Chazal have said. And even though, because they are many, his [i.e., each individual's] money does not cover the whole loan but only a [small] part of it, still, it seems clear that the Holy One Blessed be He considers each one as if he alone were the giver of the loan; for without his small amount, the poor man could not secure what he needed. [This is similar to our saying (regarding the forbidden Sabbath labors) (Shabbath 3a): "[Only] one who does the whole labor [is responsible], and not one who does [only] part of it," notwithstanding which if each one by himself cannot carry the load, the Mishnah rules that [each] is responsible. The reason is that this is not called "part" of the labor; for since without him it is impossible for the labor to be done, it is considered as if he himself did the entire labor.] And [(another reason for the superiority of gemiluth chasadim societies)] is that it is a mitzvah which one spends money for and which does not come without expenditure, its reward being far greater because of this, as written in the holy Zohar, Parshath Terumah. Also, the mitzvah [(of the society)] can be performed even when he is at work or sleeping. And aside from all these, it is well known what Midrash Koheleth says, that if a man pines for mitzvoth and has no permanent mitzvah for the generations, what pleasure can he have? But one who has a part in a mitzvah of the many, such as the one we are discussing, or one who leaves over money to support yeshivoth of Torah study — even if he is sitting in Gan Eden there is reposed upon his soul sweetness and light through the mitzvoth that are constantly fulfilled through the monies he left distinctly to this end.