The second word for Catholics and Lutherans, the third word for Judaism and for Protestants, deals with the appropriate use of God’s personal name.
Profanity is wrong, as is cursing, swearing, and cussing. But these are matters of cultural mores. This commandment is concerned with other things, namely the insincere, inauthentic, or deceitful use of God’s personal name, “Yahweh.” The appropriate use of the name is illustrated in JeremiahProphet who condemned Judah's infidelity to God, warned of Babylonian conquest, and promised a new covenant More 4:2: “…and if you swear, “As Yahweh lives!” in truth, in justice, and in uprightness, then nations shall be blessed by him, and by him they shall boast” (author’s translation). It is possible to swear using the name of the Lord, but it must be done “in truth, in justice, and in uprightness.” When so done, one involves God in the matter in question. Inappropriate use of the divine name would include using “Yahweh” in a false oath; false prophecyProphecy is the gift, inspired by God, of speaking and interpreting the divine will. Prophets such as Amos, Isaiah, and Ezekiel spoke words of judgment and comfort to the people of Israel on behalf of God. More “in the name of Yahweh”–that is, claiming divine authority for one’s own preaching; or any activity in which God’s good name is insincerely used to lend authenticity in a manipulative manner.