The Third Commandment is rooted in the First, the unique and exclusive God who alone is to be worshipped. The Second Commandment prohibits visual representations of God (or gods), while the Third focuses on verbal representations of God, with His Name as an extension of His person. Out of respect for God, God’s people are to exercise the greatest caution when talking about Him or invoking His Name.
In the Bible, the name of a person was linked to his character. The Name of God (Yahweh) was a revelation of God’s nature, and thus to use His Name in an inappropriate manner would be an insult to the character of God. This commandment addresses any insincere reference to the Lord, as His Name is the revelation of His person: