We read in Parshat Truma (Shmot 25:1-2):
God spoke to Moshe saying, “Speak to B’nei Yisrael and have them take for me a Truma offering. For every man whose heart impels him to generosity shall you take My Truma offering.”
Rabbi Yosef Patzanovski, author of Pardes Yosef explains that Parshat Truma comes right after Parshat Mishpatim (laws) to teach us that even though God loves generous people who give Tzedaka (charity/justice), God only wants us to donate money that was earned in a righteous and just manner following the laws that are outlined in the Torah. If the money was not earned ethically then there is no point in giving that money as Tzedaka. The money is tainted and is considered a “mitzvah haba’ah beaveirah”, a mitzvah that only came about through a sin. We learn in Yishayahu 59:14, “And judgement is turned away backwards, and justice stands afar off…” When judgement is turned away, the Tzedaka also stands afar and serves no purpose.
The Zohar, Vayakhel 198 quotes from Yishayahu 58:7, “Surely you should break your bread for the hungry…” It doesn’t say “bread”, rather it says “your bread”, your money, not money that is stolen, since money that was robbed does not become Tzedaka it just becomes a reminder of the theft.
In Parshat Vayakhel 35:5 we read: “Take from yourselves a Truma offering to God…” The emphasis in this verse is on “from yourselves”, from your own money.
We also see this concept in Mishlei 22:9, “One with a good eye will be blessed, for he has given of his bread to the poor.”
The Maharsha taught in Chidushei Agadot (Ketuvot 67) that many people in his generation would steal money from others and then offer it as Tzedaka. Unfortunately, this is a “mitzvah haba’ah beaveirah”, a mitzvah that only came about through a sin.
Unfortunately, some things still haven’t changed.