John Wesley on Isaiah 28:24

Doth - The plowman doth not spend all his time in plowing the ground; but he has several times for several works. And so God has his times and seasons for several works, and his providence is various at several times, and towards several people. Therefore those scoffing Israelites were guilty of great folly, in flattering themselves, because of God's long patience towards them; for God will certainly take a time to thresh, and break them with his judgments, as at present he plowed and harrowed them, and so prepared them for it by his threatenings. Open - Understand, all day. Break - Which they used to do with a kind of harrow.