'Rules' in the Bible

Now even the first covenant had regulations for divine worship and for the earthly sanctuary.

For they [the gifts, sacrifices, and ceremonies] deal only with [clean and unclean] food and drink and various ritual washings, [mere] external regulations for the body imposed [to help the worshipers] until the time of reformation [that is, the time of the new order when Christ will establish the reality of what these things foreshadow—a better covenant].

and since we have a great and wonderful Priest [Who rules] over the house of God,

Do not be carried away by diverse and strange teachings; for it is good for the heart to be established and strengthened by grace and not by foods [rules of diet and ritualistic meals], which bring no benefit or spiritual growth to those who observe them.