God not only commanded it, but earnestly protested it to their fathers, when he brought them into covenant with himself. Moses inculcated it again and again, by precept upon precept and line upon line. 3. This was made the condition of the relation between and God, which was so much their honour and privilege: “So shall you be my people and I will be your God; I will own you for mine, and you may call upon me as yours;” this intimates that, if they refused to obey, they could no longer claim the benefit of the relation.
Matthew Henry