Albert Barnes Commentary Psalms 50:9

"I will take no bullock out of thy house, Nor he-goats out of thy folds." — Psalms 50:9 (ASV)

I will take no bullock out of your house - Bullocks were offered regularly in the Hebrew service and sacrifice (Exodus 29:11), (Exodus 29:36); (Leviticus 4:4); (1 Kings 18:23), (1 Kings 18:33); and it is with reference to this that the language is used here. In obedience to the law it was right and proper to offer such sacrifices; and the design here is not to express disapprobation of these offerings in themselves considered. On this subject—on the external compliance with the law in this respect—God says (Psalms 50:8) that he had no cause to complain against them. It was only with respect to the design and the spirit with which they did this, that the language in this verse and the following verses is used.

The idea these verses aim to suggest is that God did not need such offerings; they were not to be made as if he needed them. If he did need such, he was not dependent on these offerings, for all the beasts of the earth and all the fowls of the mountains were his and could be taken for that purpose. And if he took what was claimed to be theirs—the bullocks and the goats—he did not wrong them, for all were his, and he claimed only his own.

Nor he-goats out of your folds - Goats were also offered in sacrifice (Leviticus 3:12); (Leviticus 4:24); (Leviticus 10:16); (Numbers 15:27).