Amos 1:3

1:3 For three transgressions . . . for four. This refrain, repeated with each prophecy, is an example of parallelism using ascending numbers for emphasis (cf. Ps. 62:11; Mic. 5:5). This standard device in ancient Near Eastern poetry is not intended literally, but means “for many transgressions.”

Damascus. David defeated and garrisoned this royal city of Syria (2 Sam. 8:6). During Solomon’s reign Damascus broke free, with Rezon as king (1 Kin. 11:23–25).

sledges of iron. The threshing sledge was a wooden board with teeth of iron or basalt fixed on the underside. An ox would pull the sledge over the grain while the driver stood on it. The Syrians are accused of having treated Gilead with extreme cruelty (2 Kin. 13:7).