Hadith 4:205
Waki’ narrated to us, from Ibn Abi Dhi’b, from Khalid, from Thawban, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The dawn is two dawns. As for the one that is like the tail of the wolf, it does not make anything lawful nor does it make anything unlawful. But the one that spreads (horizontally) is the one."
حدثنا وكيع عن بن أبي ذئب عن خالد عن ثوبان قال قال رسول الله صلى الله عليه وسلم الفجر فجران فأما الذي كأنه ذنب السرحان فإنه لا يحل شيئا ولا يحرمه ولكن المستطير