Musnad Abu Ya'la al-Mawsili 42:11

Zuhayr narrated to us, Sufyan narrated to us, Yahya ibn Sa'id narrated to us, from Muhammad ibn Abi Yahya: My father informed me that Abu Sa'id al-Khudri informed him that the Messenger of Allah (may Allah bless him and grant him peace), on the day of al-Hudaybiyah, said: "Do not kindle a fire at night." Then, when that had passed, he said: "Kindle [fires] and prepare food, for no one after you will ever reach [the level of] your mudd or your sa'."