Ezekiel 44:30-31

They would also receive the best parts of the firstfruits of every kind that the people brought to the Lord. The Lord would bless the people who were careful to provide the priests with their firstfruits (cf. Malachi 3:8-12; 2 Corinthians 9:10-11). Priests were not to eat any animals that died a natural death or had been slain in a way other than as a sacrifice to the Lord (cf. Leviticus 17:5; Leviticus 22:8; Deuteronomy 14:21). These animals might be inferior and might carry communicable diseases.