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 Jeremiah 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 prophecy “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.