'Observe' in the Bible

And the statutes, and the ordinances, and the law, and the commandment, which he wrote for you, ye shall observe to do for evermore; and ye shall not fear other gods.

Neither will I make the feet of Israel move any more out of the land which I gave their fathers; only if they will observe to do according to all that I have commanded them, and according to all the law that my servant Moses commanded them.