Numbers 18:25-27

Amplified Bible

²⁵ Then the Lord spoke to Moses, saying, ²⁶ “Moreover, you shall speak to the Levites and say to them, ‘When you take from the Israelites the tithe which I have given to you from them as your inheritance, then you shall present an offering from it to the Lord, a tithe of the tithe [paid by the people]. ²⁷ Your offering shall be credited to you as the grain from the threshing floor or as the full produce from the wine vat.