4:1-23 The power and love of God to Israel are here made the ground and reason of a number of cautions and serious warnings; and although there is much reference to their national covenant, yet all may be applied to those who live under the gospel. What are laws made for but to be observed and obeyed? Our obedience as individuals cannot merit salvation; but it is the only evidence that we are partakers of the gift of God, which is eternal life through Jesus Christ, Considering how many temptations we are compassed with, and what corrupt desires we have in our bosoms, we have great need to keep our hearts with all diligence. Those cannot walk aright, who walk carelessly. Moses charges particularly to take heed of the sin of idolatry. He shows how weak the temptation would be to those who thought aright; for these pretended gods, the sun, moon, and stars, were only blessings which the Lord their God had imparted to all nations. It is absurd to worship them; shall we serve those that were made to serve us? Take heed lest ye forget the covenant of the Lord your God. We must take heed lest at any time we forget our religion. Care, caution, and watchfulness, are helps against a bad memory.
16-19. Lest ye corrupt yourselves, and make you a graven image—The things are here specified of which God prohibited any image or representation to be made for the purposes of worship; and, from the variety of details entered into, an idea may be formed of the extensive prevalence of idolatry in that age. In whatever way idolatry originated, whether from an intention to worship the true God through those things which seemed to afford the strongest evidences of His power, or whether a divine principle was supposed to reside in the things themselves, there was scarcely an element or object of nature but was deified. This was particularly the case with the Canaanites and Egyptians, against whose superstitious practices the caution, no doubt, was chiefly directed. The former worshipped Baal and Astarte, the latter Osiris and Isis, under the figure of a male and a female. It was in Egypt that animal-worship most prevailed, for the natives of that country deified among beasts the ox, the heifer, the sheep, and the goat, the dog, the cat, and the ape; among birds, the ibis, the hawk, and the crane; among reptiles, the crocodile, the frog, and the beetle; among fishes, all the fish of the Nile; some of these, as Osiris and Isis, were worshipped over all Egypt, the others only in particular provinces. In addition they embraced the Zabian superstition, the adoration of the Egyptians, in common with that of many other people, extending to the whole starry host. The very circumstantial details here given of the Canaanitish and Egyptian idolatry were owing to the past and prospective familiarity of the Israelites with it in all these forms.