Vain

The concrete aspect of this is expressed in the idea of “breath” or “wind.” In Job 15:2; 16:3 the “vain” of KJV is rendered “windy” by RSV.

The practical aspect, however, is expressed much more frequently as that which is “useless,” “a failure,” or “to no avail.” The phrase “in vain” usually has this force (Job 9:29; Prov 1:17; Ezek 6:10; Rom 13:4; Gal 3:4; James 4:5; et al.). (See also Judith 6:9; Ecclus 23:11.)

The moral aspect begins with the idea of “being without value” (Judg 9:4; 11:3; 2 Chron 13:7; Prov 12:11); or “without reason” (Col 2:18; Wisd Sol 13:1).

The ancient mind seems to have reacted strongly to this. The “vain thing” was that which seemed to promise something and failed to fulfill the promise. There was, therefore, the element of “deception,” “falsehood,” and even “wickedness” in this emptiness and failure. The “vain thoughts” of KJV (Jer 4:14) become “evil thoughts” in RSV. The RSV trs. the same Heb. word “in vain” (Exod 20:7), “worthless” (Job 11:11), “false” (Psalm 26:4), “for evil” (Ps 139:20), and “delusive” (Ezek 13:7). In all these instances KJV uses the word “vain.” (See also Ecclus 34:1.)

For Bibliography and further discussion see Vanity.

International Standard Bible Encyclopedia (1915)

van: The adjective of "vanity," and representing the same Hebrew and Greek words as does the latter, with a few additions (chiefly kenos, "empty," and its compounds in the New Testament). And "vain" can always be replaced by its synonym "empty," often with advantage in modern English (Job 15:2; 1Co 15:14, etc.). The exception is the phrase "in vain," and even there the interchange can be made if some (understood) noun such as "ways" be added. So "to take God’s name in vain" (Ex 20:7; De 5:11) means simply to take it for an "empty" ("not good") purpose.