Isaiah 28:27 - Ellicott's Commentary On The Whole Bible

For the fitches are not threshed... — Better, fennel seed, as before. The eye of the prophet passes from the beginning to the end of the husbandman’s work. He finds there also the varying methods of a like discrimination. A man would be thought mad who threshed his fennel seed and cummin with the same instrument that he uses for his barley and his wheat. It is enough to beat or tap them with the “rod,” or “staff,” which was, in fact, used in each case. Interpreting this parable, we may see in the fennel and the cummin the little ones of the earth, with whom God deals more gently than with the strong. “Tribulation,” as the etymology of the word (tribulum, a threshing instrument) tells us, is a threshing process. The lesson of the parable is that it comes to nations and individuals in season and in measure. The main idea is familiar enough in the language of the prophets (Micah 4:13; Habakkuk 3:12). The novelty of Isaiah’s treatment of it consists in his bringing in the minute details, and drawing this lesson from them.