Jamieson, Fausset and Brown on Job 37:11-13

11-13. How the thunderclouds are dispersed, or else employed by God, either for correction or mercy.

by watering--by loading it with water.

wearieth--burdeneth it, so that it falls in rain; thus "wearieth" answers to the parallel "scattereth" (compare, see on Job 37:9); a clear sky resulting alike from both.

bright cloud--literally, "cloud of his light," that is, of His lightning. Umbreit for "watering," &c., translates; "Brightness drives away the clouds, His light scattereth the thick clouds"; the parallelism is thus good, but the Hebrew hardly sanctions it.