Musnad Ahmad 33:1157

Khalaf ibn al-Walid narrated to us, al-Rabi’—meaning ibn Sabih—narrated to us, from Abu al-Zubayr al-Makki, from Jabir ibn Abdullah, who said: "The Messenger of Allah (may Allah bless him and grant him peace) forbade us from eating leeks and onions." Al-Rabi’ said: So I asked ‘Ata’ about that, and he said: Jabir ibn Abdullah narrated to me: "That the Messenger of Allah (may Allah bless him and grant him peace) forbade it."