But God prepared a worm when the morning rose the next day, and it smote the gourd that it withered.
But God prepared a worm - of a particular kind, deadly to the ricinus. A small worm at the root destroys a large gourd. So it takes but little to make our creature-comforts wither. It should silence discontent, to remember that when our gourd is gone our God is not gone. Black caterpillars often in one night strip the palma-christi of its leaves, and leave only the bare ribs. The word "worm" may be here used collectively for many worms or grubs of one kind, prepared by God's providence for the destruction of the shrub.
When the morning rose the next day - after Jonah was so "exceeding glad" (cf. Psalms 30:7, "Lord, by thy favour thou hast made my mountain to stand strong; thou didst hide thy face, and I was troubled").