Saul Behr wrote:
If someone returns to Torah observance at, say, age 40, and he wants to start keeping mitzvot, how can he approach giving ma'aser (a tithe for charity)? I would imagine there's a mitzvah to return what he "stole" - i.e., the ma'aser he didn't give all the previous years. If, for example, he had been working for 20 years at the same salary, he would be indebted for two years of his salary! Could he start a clean account, or would he have to start making up the difference by giving, say, 20% instead of 10%, and coming clean by the time he was 60?
Dear Saul Behr,
In the situation you wrote about, it's not necessary for the person to "repay" the ma'aser that he had not given during all the previous years. The Shulchan Aruch says that the first year, a person should give ma'aser from his principle, and each ensuing year he should give ma'aser from his profit.
- Rabbi Yaakov Yosef Auerbach
- Shulchan Aruch Yoreh Deah 249:1