Nehemiah 10:35-36

35We will also agree to bring the first crops from our land each year and the first fruits from our trees. We will bring these to the Lord's temple.

36We will also bring our firstborn sons, as well as the first babies that our cows, sheep and goats give birth to. We will bring them to the priests who serve our God in the temple. That is what God's Law teaches us to do.