The Third Word assumes that we carry the Lord’s name. What it prohibits is bearing, carrying, or lifting that name “in vain” or “emptily.” The word can mean “false,” and bearing the name “falsely” is one of the sins that the Lord prohibits here.
That does involve speech. This phrasing is used in various places in the Old Testament to describe false oaths. When we swear in the name of the Lord, we call the Lord as a witness to the truth of what we are saying. We call on Him as a third party to defend what we say. If we’re lying, we are invoking His name emptily.
Oaths are also self-maledictory, self-cursing. When we swear, we are insisting that what we say is true, on pain of death. In taking an oath, we say, “If what I say is not true, then may the Lord’s curse fall on me.” May the living God kill me if what I speak falsely.
To take the name of the Lord emptily or lightly is to invoke God as witness for things that are false. It is to call down God’s curse without genuine fear of the Lord’s judgment. It is to swear to false things, or to swear without taking God’s name as the weighty thing that it is.
But we can be false to the name without speaking, by what we do.
Bearing the name lightly, carrying the name falsely, occurs when our lives contradict the name that we wear. We are children of the heavenly Father, and are marked with the Name of the Father, Son, and Spirit. If we act like children of the devil, then we are bearing the name falsely. We are falsifying the name of Yahweh and treating it as empty breath.
The word for this is “hypocrisy,” and it is the besetting sin of Israel during the exile and after the exile. Each age of Israel’s history is marked by a besetting sin, and they correspond to the first three of the Ten Words. During the period of the judges, Israel was constantly tempted to worship the gods of the nations, to break the First Word that prohibits putting any other gods before Yahweh. During the period of the kings, Israel was tempted to worship at high places and through the images of golden calves; they broke the Second Word.
When Israel didn’t bear the name weightily, they “profaned” the Name of Yahweh. His name is a holy name, and they polluted it by their behavior.
Behind this language of “profanation” is the connection of the Name of Yahweh with His house. In Kings, the Lord dwells in the temple by His Name. Here the Name is the title of the Second Person of the Trinity, the Son. The Father’s name is the Son. The Father’s reputation is the Son. The Father’s self-disclosing identification is the Son.
This name dwelt in the temple, and sanctified the temple by His presence. Because the Name was in the house, the house had to be kept clean. Sins had to be scoured from the house. The priests had to maintain the cycle of offerings, the lamps on the lampstand, the showbread on the table. If Israel and the priests failed to maintain the house, the house would become polluted and the name profaned.
Each Israelite was a house, named by the Name. In the New Covenant, we are all named by the Name of the Trinity, indwelt by the Spirit, who consecrates us as His dwelling place. God’s name, His reputation, is bound up with our behavior.