Charles Spurgeon Commentary Jonah 4:6

"And Jehovah God prepared a gourd, and made it to come up over Jonah, that it might be a shade over his head, to deliver him from his evil case. So Jonah was exceeding glad because of the gourd." — Jonah 4:6 (ASV)

Those who are angry with God show the littleness of their minds. "Little things please little minds," so a gourd made Jonah glad.