'Rules' in the Bible

And though by this time it would be right for you to be teachers, you still have need of someone to give you teaching about the first simple rules of God's revelation; you have become like babies who have need of milk, and not of solid food.

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].

For when Moses had given all the rules of the law to the people, he took the blood of goats and young oxen, with water and red wool and hyssop, and put it on the book itself and on all the people,

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.