Likewise a farmer threshes dill, cummin, and grain in different ways. This is also wisdom that Yahweh of armies teaches. A simple farmer learns how to plow, plant, thresh, and grind from God, by studying nature, and as he applies what God teaches, there is blessing. How much more should the sophisticated leaders of Judah learn from Him to trust Him. [source][source][source]
". . . God measures the instruments of His purpose to the condition of His people; He employs what will best carry out His holy will." [1][source]
"The farmer does not plow for the sake of plowing, but rather to prepare for his intended crop. So also God prepares his garden for the crop he wishes to reap-the crop of righteousness from a holy people. To this end God must employ the cutting and crumbling force of disciplinary judgments, perfectly adjusted to Israel"s spiritual needs, just as the farmer (using the intelligence God gave him) uses the proper threshing instruments for each type of grain." [2][source]
An implication of these two parables ( Isaiah 28:24-25; Isaiah 28:27-28), not stated, is that God might deal differently with the Southern Kingdom than He dealt with the Northern Kingdom. The Jerusalemites should not conclude that because God would allow the Assyrians to defeat the Ephraimites, the same fate would necessarily befall them. A change of attitude could mitigate their judgment. So this whole "woe" ends with an implied offer of grace. [source][source][source]
As things worked out, of course, God did allow an invading army to take the Judahites into captivity, after a different invading army had first taken the Israelites captive. But that did not happen at the same time. Sennacherib destroyed Samaria but not Jerusalem. God postponed Judah"s judgment because He found a measure of repentance there. [source][source][source]