Musnad Ahmad 768:1

Sufyan ibn 'Uyaynah narrated to us, from Isma'il—meaning Ibn Abi Khalid—from Hakim ibn Jabir, from his father, who said: I entered upon the Messenger of Allah, may Allah bless him and grant him peace, and he had with him some pumpkin (dabba'). I said: "What is this?" He said: "We increase our food with it."