Malachi 3:8-10

Will a man rob God? Yet ye have robbed me. But Ye say, Wherein have we robbed the? In tithes and offerings.

Ye are cursed with a curse: for ye have robbed me, event this whole nation.

Bring ye all the tithes into the storehouse, that there may be meat in mine house, and prove me now herewith, saith the LORD of host, if I will not open you the windows of heaven, and pour you out a blessing, that there shall not be room enough to receive it

Deuteronomy 16:17

Every man shall give as he is able, according to the blessing of the Lord thy God, which he hath given thee.

II Corinthians 9:7

Every man according as he purposeth in his heart, so let him give; not grudgingly, or necessity; for God loveth a cheerful giver.