The Hebrew verb for "bless" is "berek" (). Since in Assyrian and Minæan the corresponding verb appears to be "karabu," it is not likely that the Hebrew is connected with its homonym "berek" (), which means "knee" The substantive "blessing" is "berakah" (). "To curse" is "arar" (); sub-stantives are "ḳelalah" (), "me'erah" (). Synonyms are ; and it is note-worthy that the word "curse" should have numerous synonyms, whereas for "bless" we have only one word. Both "blessing" and "cursing" were founded upon the belief that the individual, the tribe, or the nation could use its relation to the Deity or to the supernatural world for the benefit or the injury of others. It is readily understood that special efficacy attached to the blessing and cursing by sacred persons in close relations with the Deity—by the Patriarchs, by Moses, and by Aaron, by the priests and the Prophets in general, and also by a father; for not only was the father the priest of the family,but it was he who introduced his son to the Deity; and naturally it was supposed that he could influence the Deity to his son's benefit or injury.
Such blessing or cursing did not involve the use of empty words, but implied the exercise of a real power; the word once pronounced was no more under the control of the speaker (Gen. xxvii. 35), and must perforce accomplish its mission. On this conception is founded not only the possibility but also the whole structure of Jacob's deceit, as well as the story of Balaam. Even in later times the possibility seemed dreadful that Balaam, instead of blessing, might have cursed (Micah vi. 5; Neh. xiii. 2). At the same time the story of Jacob proves that blessing and cursing did not always rest on moral grounds. Noah (Gen. ix. 22 et seq.) and Jacob (Gen. xlix. 2 et seq.), it is true, were guided by the moral conduct of their sons; but Isaac was governed by caprice in his blessings. He was moved by the venison which Esau was to bring him and by his son's affectionate manner (Gen. xxvii. 26 et seq.).
Since cursing was considered a material power the unknown thief was cursed; and the mother of the Ephraimite Micah hastened to render the curse ineffective by a blessing after her son had confessed his sin (Judges xvii. 2). For this reason every alliance and every oath was accompanied by a curse directed against the person who should break the alliance or violate the oath; and the laws of Israel, and the treaties of the Assyrian and the Babylonians (compare Schrader, "K. B." vols. ii. and iii. passim), derived particular strength from the addition of a blessing and a curse (Lev. xxvi.; Deut. xi. 29 [compare 28]; Josh. viii. 34). Goliath cursed David "by his gods" (Sam. xvii. 43), and Balak desired Balaam to curse the Israelites, the enemies of Moab (Num. xxii. 6), because cursing was supposed to move the divine power for the injury of the enemy. Hence severe punishment was inflicted on those who cursed their parents (Ex. xxi. 17; Lev. xx. 9; compare Deut. xxvii. 16) or the authorities (Ex. xxii. 28).
However, with the gradual development of pure monotheism the conception of blessing and cursing came to be modified. While in early times it was the belief that a father by his blessings or his curses determined the fate of his son (Gen. xlix. 4, 7; Prov. xxx. 11), in later times the father became a seer (Gen. xlix. 1, xlviii. 17 et seq.). In fact, Prov. xxvi. 2, distinctly declares that "the causeless curse" will not be fulfilled.