Sunan Ibn Majah, Chapter: The Chapters on Food

that Umar bin Khattab stood up one Friday delivering a sermon. He praised and glorified Allah, then he said: "O people, you eat two plants which I do not regard as anything but offensive: This garlic and these onions. At the time of the Messenger of Allah (saw), I would see a man, if the smell (of these vegetables) was found on him, being taken by the hand and led out to Baqi' (graveyard). Whoever must eat them, let him cook them to death."