You shall have no other gods before Me.
Exodus 20:3 Thou shalt have no other gods before me. In this commandment God enjoins that He alone should be worshipped, and requires a worship free from all superstition. For although it seems to be a simple prohibition, yet must we deduce an affirmation from the negative, as will be more apparent from the following words.
Here is, I. The preface of the law-writer, Moses: God spoke all these words, Exo 20:1. The law of the ten commandments is, 1. A law of God's making. They are enjoined by the infinite eternal Majesty of heaven and earth. And where the word of the King of kings is surely there is power. 2. It is a law of his own speaking.
Commenting on Exodus 20:1-11
Thou shalt have no other gods before me. This is the first command, and is opposed to the polytheism of the Gentiles, the Egyptians, from whom Israel was just come, and whose gods some of them might have had a favourable opinion of and liking to, and had committed idolatry with; and the Canaanites, into whose land they were going; and to prevent their joining...