Premanand Maharaj Ji
How should I earn and give a part of my money in dharma?
Earn righteously, give a tenth
Earn by honest effort and give a tenth of it to dharma, as the scriptures instruct. Money earned through sin can even harm the one who receives it.
If we earn 100 rupees by righteous means, we can spend 1 rupee in the service of a guest, a sick person, or a saint.