Why God Commands Sacrifices Though the Whole World Is His

(Numbers 28:1-2:) "And the LORD spoke to Moses, saying: Command the children of Israel, and say to them: My offering, My bread for My fire-offerings, etc." Let our master teach us: The meal offerings that were offered upon the altar, how were they offered? Thus have our Rabbis taught: All meal offerings come unleavened, except for the leaven in the thank offering and the two loaves, which come leavened. Rabbi Meir says: The leaven is separated out from within them, and from it they are leavened. Rabbi Judah says: Even that is not the choicest way; rather, one brings the leaven and places it into the measure and fills the measure. They said to him: Even that would be either deficient or excessive. All meal offerings are kneaded in lukewarm water, and one watches over them so that they do not become leavened; and if their remainder became leavened, one transgresses a negative commandment, as it is said (Leviticus 2:11): "No meal offering which you offer to the LORD shall be made with leaven." And one is liable for its kneading, and for its arranging, and for its baking. And you have none more beloved among all the offerings than the thank offering. The Holy One, blessed be He, said to Moses: Say to Israel: It is not because I have need of you that I told you to offer Me offerings, for the whole world is entirely Mine, as it is said (Psalms 50:12): "If I were hungry, I would not tell you, for the world and its fullness are Mine."