Tithe: Antiquity of the Custom of Giving to God's Ministers
Source: TTT
Genesis 14:20
and blessed be God Most High, who has delivered your enemies into your hand.” Then Abram gave Melchizedek a tenth of everything.
Hebrews 7:6
But Melchizedek, who did not trace his descent from Levi, collected a tenth from Abraham and blessed him who had the promises.