سنن ابودوٗد · Hadith 690

This tradition has also been reported by Abu Hurairah through a different chain of narrators. Abu Hurairah reported: The Prophet ﷺ said: . . . . . . He then narrated the tradition about drawing the line. Sufyan said: We did not find anything by which we could reinforce this tradition, and this has been narrated only through this chain. He (Ali bin al-Madini, a narrator) said: I said to Sufyan: There is a difference of opinion of the name (Abu Muhammad bin Amr). He pondered for a moment and then said: I do not remember except Abu Muhammad bin Amr Sufyan said: A man had come to Kufah after the death of Ismail bin Umayyah ; he was seeking Abu Muhammad until he found him. He asked him (about this tradition) but he became confused. Abu Dawud said: I heard Ahmad bin Hanbal who was questioned many times how the line should be drawn. He replied: In this way. horizontally like crescent. Abu Dawud said: I heard Musaddad say: Ibn Dawud said: The line should be drawn perpendicularly. Abu Dawud said: I heard Ahmad bin Hanbal describing many times how the line should be drawn. He said: In this way horizontally in the round semi-circular form like the crescent, that is (the line should be) a curve.