1) The poskim discuss the nature of the obligation to give ten percent of one’s money to charity (Maaser money) A- Tosafos (Taanis 9a) quotes the Sifri that there is an obligation to give ma’aser on all money acquired through business transactions and the like. The Sifri derives this from a verse in Devarim 22:14 “You shall tithe all the seed crops that the field gives forth, year by year”. It would seem that the Sifri holds that the obligation to give ma’aser kesafim is biblical in nature. Indeed, the Chasam Sofer (Yoreh Deah 232) writes that according to the Maharil the obligation is from the Torah. B- The opinion of the Bach (Yoreh Deah 331) is that ma’aser kesafim is neither biblical nor rabbinic (rather it is a custom). His son-in-law, the Ta’z, in his commentary on Shulchan Aruch (Yoreh Deah 331:32) questions his father-in-law’s opinion and he therefore holds that the obligation is rabbinic (as explained by Chavos Yair 234, see however Aruch Hashulchan Y.D. 331 for a dissenting view). The Noda B’Yehuda agrees with the Ta’z that the obligation is merely rabbinic (cited by Tzitz Eliezer 9:1) Many Authorities agree with the Bach and explain that ma’aser kesafim is simply a custom, including: Sheilas Yaavetz (1:6), Shvus Yaakov (vol. 2 Yoreh Deah 85), Shut Pnei Yehoshua (Orach Chaim 2).
2) The Chavos Yair (234) and the Teshuva Me’Ahava (1:85) both write that even according to the Bach (who contends that ma’aser kefafim is purely a custom) once one begins to give ma’aser, it is as if he made an oath to do so and is now obligated to continue. Many are of the opinion that this is true immediately after the first time one gives ma’aser. It is for this reason that the Chofetz Chayim (in his sefer Ahavas Chesed chapter 18 note 2) advises that one should stipulate – prior to the first time he gives ma’aser – that he is doing so “Bli Neder”, without the binding force of a vow. If he fails to make this stipulation, he becomes obligated to give ma’aser as if he had vowed to give a tenth of his money to tzedaka, and all the stringencies that apply when fulfilling a pure obligation command would apply to him.
3) The poskim discuss whether one may purchase seforim using Maaser money. A- Rama (Yoreh Deah 249) rules that ma’aser should be given to poor people and it is not to be spent on other mitzvos. Purchasing seforim should therefore be forbidden. A stringent view was advanced by the Aruch Hashulchan who feels that purchasing seforim is an inappropriate use of ma’aser. Rather the money should go to the poor (an almost identical ruling to that of the Rama previously cited). B- The Shach, however, permitted buying seforim from ma’aser money on the condition that one lends it out to others. The Ta’z has a similar lenient ruling and adds that one must mark in the sefer that it was bought using money from ma’aser. This will ensure that even his children will always remember that the sefer does not belong to him and is meant to be used by the public. C- The Chofetz Chayim writes that if one knows someone who cannot afford to buy seforim, one may purchase seforim using ma’aser money, and then lend it to said person. He explains that this is an acceptable form of tzedaka. D -It is also worthy to note that based on a teaching of the Chasam Sofer (Yoreh Deah 231) one may stipulate – prior to the first time he gives ma’aser – that he intends to use the money for other mitzvos. This too should bypass all issues.
4) Rav Shmuel Wosner zt”l in his sefer Shevet Halevi (7:195) writes that one is allowed to purchase seforim (using ma’aser money) and donate them to a shul or yeshiva according to all authorities. He explains that the Aruch Hashulchan ruled stringently only when the person intended on owning the sefer and lending it out to others. The Aruch Hashulchan feared that over time he might forget to lend it to others and the sefer will become “one of his own”. However, donating the seforim to a shul or a yeshiva would avoid this problem.
5) Rav Moshe Feinstein zt”l (Igros Moshe Yoreh Deah 2:113) writes that one is not allowed to use ma’aser to pay tuition for one’s son to go to yeshiva. This restriction is based on the halachic principle that ma’aser money may not be used to pay off an earlier obligation; and since one is required to pay for a child’s education, one may not fulfill his obligation using ma’aser money. A similar ruling is advanced by the Chafetz Chayim in his sefer Ahavas Chesed (19:2).
6) Rav Moshe extends a similar ruling regarding tuition for one’s daughter to go to “Bais Yaakov”. He explains that although one is not obligated to teach his daughter Torah, however, one is obligated to insure that his daughter is raised in a religious environment. In America one is required by law to send his children to a school, if not private than public. Therefore one is obligated to send his daughter to a religious private school if the alternative is a public school. The halacha of a girl is identical to that of the boy, that one may not fulfill his obligation to pay for a child’s education with ma’aser money.
If one finds himself having a difficult time paying tuition and feels that he needs to use some ma’aser money as aid, there are authorities who are lenient. (See Rivevos Efraim 4:204) However, a rav should be consulted before taking a lenient approach. Rav Moshe adds that one may use Maaser money for the tuition that is above the standard fare.
7) Rav Moshe Feinstein zt’l in his sefer Igros Moshe (Orach Chaim 4:76 no. 2) addresses the permissibility of purchasing tickets at a Chinese auction (organized by a tzedaka organization) using ma’aser money. He writes that it is permissible to do so and the winnings do not belong to ma’aser. He adds that if one wins a prize with this ticket that he should reimburse the price of the ticket to his “ma’aser funds”.
8) Rav Moshe Shternbuch shlit”a (Teshuvos V’Hanhagos 3:289) agrees with Rav Moshe in principle, however, he voices his concern that people will only give ma’aser to those organizations who organized an auction, leaving many worthy causes without donators. He advises, therefore, to only spend a fifth of one’s ma’aser funds at auctions and events. It goes without saying that one should not give to a lesser cause basing his decision on the fact that they have organized an auction; rather the money should go to the most worthy cause.
9) As with any other business transaction, a shadchan must be paid a fee for arranging a shidduch (Rama C.M. 185)
10) One is not allowed to use maaser money to pay for obligations and debts. Therefore, one is not allowed to pay the shadchan with maaser money. (Zichron Yehuda 192 and Emes L’Yaakov on Tzedaka) Harav Gavriel Zinner shlit”a rules that if one agrees to pay the shadchan more than is the standard fair, he may use maaser money to pay the amount that is above the standard fair. (Netai Gavriel Tenaim page 386)