Musnad Ahmad 31:821

Abu Sa’id narrated to us, ‘Abdullah ibn Ja’far narrated to us, Yazid ibn ‘Abdullah narrated to us, from ‘Abdullah ibn Khabbab, from Abu Sa’id al-Khudri, that the Messenger of Allah (may Allah bless him and grant him peace) forbade *wisal* (continuous fasting without breaking it at night). He said: "Whoever cannot avoid *wisal*, let him continue from the pre-dawn time (*sahar*) to the pre-dawn time (*sahar*)." It was said: "O Messenger of Allah, you perform *wisal*." He said: "I am not like you. I spend the night while I have one who feeds me and one who gives me to drink."