'Eternal' in the Bible

But still I will keep in mind the agreement made with you in the days when you were young, and I will make with you an eternal agreement.

And I will make an agreement of peace with them: it will be an eternal agreement with them: and I will have mercy on them and make their numbers great, and will put my holy place among them for ever.

And you are to give, morning by morning, a meal offering with it, a sixth of an ephah and a third of a hin of oil dropped on the best meal; a meal offering offered to the Lord at all times by an eternal order.