John Calvin viewed “I am the Lord thy God” as a preface to the Decalogue and “have no other gods” as the first commandment. However, he also allowed for viewing “I am the Lord thy God” as the first commandment, provided one also allows it to serve as a preface to the whole Decalogue. In his commentary on the first commandment, Calvin describes superstition as akin to a wife committing adultery in front of her husband.
Martin Luther describes the first commandment as prohibiting both the literal honoring of other gods as well as trusting in idols of the heart: money, good works, superstition, etc. Like Calvin,
Matthew Henry considers “I am the Lord thy God” to be a preface. Henry explains the preface and the first commandment from a covenant viewpoint: God delivered Israel from Egypt, and they belong to him by mutual agreement, so they are bound to obey his covenant stipulations.
John Wesley makes the common observation that Israel is obligated to obey God's commandments because he delivered them from Egypt, and he adds the observation that Christians are likewise obligated to serve Christ, having been rescued out of bondage to sin. John Wesley uses the first commandment in Deuteronomy 5 as a motivation to pose a list of introspective questions. In his exposition of Exodus 20 on the “Thru The Bible” radio program,
J. Vernon McGee, quotes Romans 1:21-25 and Colossians 3:5 to support his assertion that the idolatry forbidden by the first commandment includes not only the worship of idols and foreign gods, but also idols of the heart such as greed, alcohol, and sexual immorality. ==Jewish doctrine==