I rented a machsan for many years to a person who makes batim for tefilin. He was always late with rent but eventually paid. More than a year ago, he became sick and is no longer able to work. He owes well over NIS 2,000 and claims he will pay for it but as of yet as done so. I do not think he has any source of income and his wife is not well. This indvidual is a very ehrlich person and I want to relieve him of his debt even though I do want the rent. Can I take the “loss” off of maeser money as if I was giving it to him (even though I am gaining form it) or if I want to relieve him of his debt to do so without calculation of maeser money.
There is much controversy if one may deduct a debt that is owed to him from maaser money. According to some poskim one may only deduct the debt if he had in mind at the time of giving the money (or the rent) that if eventually the money would not be paid, that he would use the debt a maaser . Others argue on this, that it would be permitted but under certain conditions, see sources. Others say that it is permitted, but only if the poor person would be able to pay back the loan. in your case since he is sick and his wife is sick it might be considered as if he can’t repay it. Therefore in your case it seems that all would agree that you shouldn’t deduct the debt from maaser money.
There are however some options. You could make an anonymous (without people knowing who the poor person is) collection in order to pay the debt of the poor person (see Imrei Tzedakah pg. 172). Another option would be to give that amount of money to the poor person, in order that he use the money to repay the debt.
See Rema Y:D 257-5 and Shach 11&12, that one may not deduct maaser unless he had in mind when he lent the money. Igros Moshe Y:D 1- 153 says that it is difficult to go against the Shach, also see Teshuvos Vhanhagos 1-560(11). Noda Byehudah 2-199 brought in Pischei Teshuva ibid 5, argues and gives two conditions, that he lets the poor person know what he is doing, and secondly he would have given the poor person this amount of money in any case. See Mashiv Davar 2-49 and Minchas Yitzchok 5-34 who give other conditions. R’ S.Z. Auerbach zt”l held that if the person would be able to pay back the loan, but if the poor person would not be able to pay back the loan (he went bankrupt, or died etc,) it is like giving tzedakah to make back money that was already lost. See B’orach Tzedakah 11-108. Also see Beis Dino Shel Shlomo Y:D 1 psakim 15.
Regarding giving the money to the poor person so he can give it back to you, see Minchas Yitzchok 5-34, and Tzedakah Umishpat 5 ftnt. 50. Regarding giving the money to someone else in order to acquire it for the poor person and then give it back to you see Tzedakah Umishpat ibid, who discusses if this may be done or not.