12 Yahweh spoke to you out of the midst of the fire: you heard the voice of words, but you saw no form; only you heard a voice. 13 He declared to you his covenant, which he commanded you to perform, even the ten commandments; and he wrote them on two tables of stone. 14 Yahweh commanded me at that time to teach you statutes and ordinances, that you might do them in the land where you go over to possess it.
15 Take therefore good heed to yourselves; for you saw no manner of form on the day that Yahweh spoke to you in Horeb out of the midst of the fire. 16 Lest you corrupt yourselves, and make yourself an engraved image in the form of any figure, the likeness of male or female, 17 the likeness of any animal that is on the earth, the likeness of any winged bird that flies in the sky, 18 the likeness of anything that creeps on the ground, the likeness of any fish that is in the water under the earth; 19 and lest you lift up your eyes to the sky, and when you see the sun and the moon and the stars, even all the army of the sky, you are drawn away and worship them, and serve them, which Yahweh your God has allotted to all the peoples under the whole sky.
Matthew Henry's Commentary on Deuteronomy 4:12-19
Commentary on Deuteronomy 4:1-23
(Read Deuteronomy 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.