Can the cost of purchasing a set of tefillin for my son as he approaches bar mitzvah be paid from ma’aser money? Why or why not?
Essentially we are not allowed to use maaser money for our personal mitzvos, such as buying tefillin, tzittis, or a lulav and etrog. Regarding buying a mitzvah item, for one’s child, there are different opinions about this, however the consensus is that one should not use his maaser money for his children’s expenses. R. M. Feinstein zt”l held that one may not use maaser money to pay for his children’s expenses that are living at home and are of the age that nowadays are usually supported by the parents. Therefore essentially a father should not use maaser money for his child’s tefillin. There is an opinion though, that although the actual tefillin should not be paid for with maaser money, however if one is financially tight, he may use maaser money to pay for the hidurim of the tefillin from maaser money. For example if regular tefillin cost $400 and he pays $600 for them, that he may use the extra $200 from maaser money.
Y:D 249-1, Lvush ibid, Shach ibid3, Taz -1, Birkei Yosef ibid 18, Aruch Hashulchan ibid 7, Ahavas Chesed 19 ftnt.1, Igros Moshe Y:D 1 143, Derech Emunah Matnas Aniyim 7ftnt. 57 in the name of the Chazon Ish, B’orach Tzedakah 11-16.