'Observe' in the Bible

The statutes and the ordinances, and the law and the commandment, which he wrote for you, you shall observe to do forevermore. You shall not fear other gods.

neither will I cause the feet of Israel to wander any more out of the land which I gave their fathers, if only 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."