'Commandment' in the Bible

The descendants of Levi who accept the priesthood have a commandment in the Law to collect a tenth from the people, that is, from their own brothers, even though they are also descendants of Abraham.

Indeed, because it was weak and ineffective, the former commandment has been annulled,

For after every commandment in the Law had been spoken to all the people by Moses, he took the blood of calves and goats, together with some water, scarlet wool, and branches of hyssop, and sprinkled the scroll and all the people,