15. Forgiving a debt. If a poor person owes someone money but cannot pay him back, the creditor may forgive the loan and deduct the amount from maaser (רמ"א יו"ד סי' רנ"ז ס"ה ). Some says this is only true if he had this in mind when he loaned the money (ש"ך סקי"ב ); others permit it even if he did not have it in mind (שו"ת אג"מ יו"ד ח"א סי' קנ"ג ).
16. If the poor man died or it becomes known that he made money (רמ"א שם ), or if the lender despaired of receiving the money, he may not then deduct the amount from maaser (דרך אמונה פ"ח צ יה"ל ס"ק רפ"ח ).
17. Items for a gemach. If one donates a used item to a gemach, he may deduct its current value [not its original value] from maaser.
18. Buying from a poor person. One may buy something from a poor person and overpay, deducting the difference from maaser, as long as there are no other considerations (שו"ת מהר"ם שי ק יו"ד סי' ר"ל ).
