The (tax) laws of the people of Israel has a rule that everybody should bring 10 % of their income to the temple as wages for the tribe of Levi. The Levites didn’t have land because they were chosen to serve in the temple and because of that they weren’t able to earn their own income. (Numbers 18:20-21) And the foreigner, the fatherless and the widow as well are supported with these gifts, because they also didn’t have their own source of income. (Deuteronomy 26:12)
Like all the rules of the Old Testament this also had gotten its own interpretation. Pharisees in Jesus’ time took it so far that they even gave tithes of their little herbs gardens. Better safe than sorry, they must have thought, afraid to be confronted with the curse of not to keeping the law. (Matthew 23:23) read more