John Calvin Commentary Joel 1:10

"The field is laid waste, the land mourneth; for the grain is destroyed, the new wine is dried up, the oil languisheth." — Joel 1:10 (ASV)

The Prophet continues here with the same subject and uses so many words to give more impact to what he said. He knew that he was addressing those who were deaf—who, through long habit, had so hardened themselves that God could accomplish nothing, or at least very little, by His word. This is why the Prophet so earnestly emphasizes a subject so evident.

If anyone should ask what need there was for so many expressions, since it seems to be an unnecessary use of words, I indeed admit that everything the Prophet wished to say could have been expressed in one sentence, as there is nothing intricate here. But it was not enough for what he said to be understood unless the Jews applied it to themselves and perceived that they were dealing with God; and they were not inclined to make this application. It is not, then, without reason that the Prophet labors here and reinforces the same thing with many words.

Therefore, he says, The field is wasted, and the land mourns; for the corn has perished, for dried up has the wine, for destroyed has been the oil. And by these words, he implies that, though seeing, they perceived nothing; as if he were saying, “Let necessity extort mourning from you. You are indeed starving; all complain of want, all deplore the need of bread and wine. And yet no one of you considers from where this want comes—that it is from the hand of God. You feel it in your mouth, you feel it in your palate, you feel it in your throat, you feel it in your stomach; but you do not feel it in your heart.”

In short, the Prophet implies that the Jews were devoid of right understanding. They indeed lamented their famine, but they were like brute beasts, which, when hungry, show signs of impatience. So the Jews mourned because their stomachs troubled them, but they did not know that the cause of their want and famine was their sins.