Hadith 4:176
9042. Sahl ibn Yusuf narrated to us, from ‘Amr, from al-Hasan, regarding a man who ate the pre-dawn meal (suhur) while he thought that it was still night: He said, "He shall complete his fast."
حدثنا سهل بن يوسف عن عمرو عن الحسن في رجل تسحر وهو يرى ان عليه ليلا قال يتم صومه