Doth the ploughman plough all day to sow?.... Or, "every day"; he ploughs in order to sow; by ploughing he prepares the ground for sowing, that is his end in ploughing; and he may plough a whole day together when he is at it, but he does not plough every day in the year; he has other work to do besides ploughing, as is later mentioned; such as breaking of clods, sowing seed, and threshing the grain after it is ripe, and reaped, and gathered.
The prophet signifies that the Lord, like a ploughman, had different sorts of work; he was not always doing one and the same thing; and particularly, that he would not be always admonishing and threatening men, and making preparation for his judgments, but in a little time he would execute them, signified by after metaphors:doth he open and break the clods of his ground?
he does, with a mallet or iron bar, or with the harrow; whereby the ground is made even, and so more fit for sowing.