The third commandment deals with God's name, His character, His office, His position as the great sovereign Ruler of the universe: "You shall not take the name of the LORD your God in vain, for the LORD will not hold him guiltless who takes His name in vain" (Exodus 20:7; Deuteronomy 5:11). In biblical terms, personal names have a meaning, for they usually describe some aspect of the person's character. So it is with God's name. The Bible reveals Him under different names, each given with a purpose: to set forth some distinct virtue or characteristic of His nature.
In this commandment, the Hebrew word rendered "guiltless" may also be translated "clean." A person is clean or unclean according to how he uses the name of God, whether in truth or in vanity. A person who continually talks about God but denies Him in his daily life is unclean; he is guilty of breaking the law of God, a sinner. If we use God's name in a way that denies the true meaning and character of God, we break the third commandment. As we can easily see, God is greatly concerned about how we use His name.
Martin G. Collins
The Third Commandment
Other Forerunner Commentary entries containing Deuteronomy 5:11: