By his powerful word and will the snow is made in the air, and falls upon the earth where and when he seeth fit. The great rain of his strength, i.e. those great storms or showers of rain which come with great force and irresistible violence.
Related Commentaries of Job 37:6
Job 37:6
6 For he saith to the snow, Be thou on the earth; likewise to the small rain, and to the great rain of his strength.