Numbers 18:13

that you shall take some of the first of all the fruit of the ground which you bring in from your land that Yahweh your God gives you, and you shall put it in a basket and go to the place where Yahweh your God chooses for His name to dwell.

“And the first of all the first fruits of every kind and every contribution of every kind, from all your contributions, shall be for the priests; you shall also give to the priest the first of your dough to cause a blessing to rest on your house.

Do you not know that those who perform sacred services eat the food of the temple, and those who attend regularly to the altar have their share from the altar?