Musnad Ahmad 32:1172

Yazid ibn Harun narrated to us, Hammad ibn Zayd informed us, from Salam al-Alawi, from Anas ibn Malik, who said: "Gourd was among the most beloved of foods to the Messenger of Allah, may Allah bless him and grant him peace," or "Gourd used to please the Messenger of Allah, may Allah bless him and grant him peace" — Yazid was in doubt — "so a bowl containing gourd was brought, and I saw him inserting his two fingers into the broth, searching for the gourd with them, the index and the middle finger; he separated them, then he brought them together."