The Hebrew words that are rendered “plague” or “scourge” have the literal meanings “touching,” “smiting,” “blow,” “defeat,” and “death.” Jehovah God dealt blows as a punishment for rebellious murmuring (Nu 16:41-50), refusal to comply with his will (Zec 14:12, 15, 18), the profane use of something sacred (1Sa 5:1–6:4), touching his anointed ones (Ge 12:17; Ps 105:15), and unfaithfulness or violations of his law (Le 26:21; Nu 14:36, 37; 31:16; De 28:59-61; 1Ch 21:17, 22; 2Ch 21:12-15). Such blows might be administered by angelic or by human means. (2Sa 24:17; Jer 19:1-8; 25:8, 9; 49:17; 50:13, 14) Prayers of intercession by Jehovah’s servants or sincere prayers by repentant ones were required for the removal of plagues sent by God.​—Ge 20:17, 18; 1Ki 8:37, 38; 2Ch 6:28, 29.

A plague could also result from the natural outworking of a person’s sin. (Pr 6:32, 33) It could be an affliction, such as “the plague of leprosy” (Le 13:2), or an adversity resulting from time and circumstance.​—Ps 38:11; 73:5, 14.

The plagues Jehovah visited upon Egypt in the time of Moses were manifestations of his great power and caused his name to be declared among the nations. (Ex 9:14, 16) For generations afterward their effects were talked about by other peoples. (Jos 2:9-11; 9:9; 1Sa 4:8; 6:6) Also, these plagues proved that the gods of Egypt were powerless.​—Ex 12:12; Nu 33:4; see GODS AND GODDESSES (The Ten Plagues); MOSES (Before Pharaoh of Egypt).

The plagues (Gr., ple·gaiʹ, literally, “blows or strokes”) mentioned in the book of Revelation evidently are expressions of God’s anger and symbolically point to the result or effect of his judicial decisions.​—Re 9:18, 20; 11:6; 15:1, 6, 8; 16:9, 21; 18:4, 8; 21:9; 22:18.