'Perpetually' in the Bible

This day will become a memorial for you, and you will celebrate it as a festival to the Lord -- you will celebrate it perpetually as a lasting ordinance.

So you will keep the Feast of Unleavened Bread, because on this very day I brought your regiments out from the land of Egypt, and so you must keep this day perpetually as a lasting ordinance.

It shall be for Aaron and his sons as their due portion from the Israelites forever, for it is a heave offering. It shall be a heave offering to the Lord from the Israelites from the sacrifices of their peace offerings.