Deuteronomy 14:28
"At the end of every three years you shall bring out all the tithe of your produce in the same year and lay it up within your towns.
Deuteronomy 14:22
"You shall tithe all the yield of your seed that comes from the field year by year.
Amos 4:4
"Come to Bethel, and transgress; to Gilgal, and multiply transgression; bring your sacrifices every morning, your tithes every three days;
Deuteronomy 26:12-15
"When you have finished paying all the tithe of your produce in the third year, which is the year of tithing, giving it to the Levite, the sojourner, the fatherless, and the widow, so that they may eat within your towns and be filled,