I’ve heard that I can use maaser money to donate to a Torah organization by buying tickets in their Chinese auction.
If I don’t know how many tickets they are selling, and have no way of finding out how many are sold, (I do know there is essentially an unlimited amount of tickets being sold), can I use 100% maaser funds to purchase the tickets, or do I need to supplement with my own money since I am receiving benefit. If so, what percentage of the ticket value should I supplement with my own money?
This is a good question.
Rav Moshe Feinstein (Orach Chaim 4:76) writes that if there is an unlimited number of participants in the lottery, it is permitted to use maaser money, because the ticket “has no price.”
In Tzedakah U-Mishpat (1:note 85) a subjective measure is used, meaning that one should subtract the amount one is ready to spend on the ticket from the maaser money. Thus, if one would be prepared to make the donation irrespective of the lottery, there is no need to subtract anything.
Some write that if one uses maaser money for a lottery ticket, the prize will belong to tzedakah (see Even Yisrael 8:64; see also the above Iggros Moshe concerning tickets that do have a price). However, this is not agreed on by other authorities.