Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Anas that the Noble Prophet (peace and blessings be upon him) was asked about the time of the Fajr prayer. So he instructed Hazrat Bilal to give the call to prayer (adhan) when the dawn appeared, and then on the next day to give the adhan when it became light. Then he said, "Where is the one who asked the question? The time for Fajr is between these two times."

(3258) [*] Al-Mu'tamir narrated to us from Ayyub from Abu Qilabah (that) (1) a man came to Abu Bakr and said: I saw in my sleep as if I was urinating blood. He said: I see that you approach your wife while she is menstruating. He said: Yes. He said: Then fear Allah (and do not do it again) (2) (3).