That Abū Dāwūd just mentioned is Nufayʿ al-Aʿmā. He has been discarded, and Ibn Maʿīn went so far as to call him a liar. There is yet another point of divergence in the material narrated from Zayd ibn Aslam; al-Zaylaʿī notes it in Nasb al-Rayah (1/236), and the reader may consult it there.

In short, the report is marked by considerable inconsistency. The soundest chain, from an isnād standpoint, is the one transmitted by Ibn ʿAjlān through ʿĀṣim ibn ʿUmar, from Maḥmūd ibn Labīd, from Rāfiʿ ibn Khadīj. Two factors commend it: (1) its continuity, and (2) its agreement—both in wording and in chain—with the narration of Abū Ghassān from Zayd ibn Aslam, save that the latter leaves unnamed some of the Companions who relate from the Prophet ﷺ. That anonymity is no serious contradiction, as is obvious, and the chain is authentic, as affirmed in Nasb al-Rayah (238).

The ḥadīth possesses many supporting narrations, though none of their isnāds is free from comment. Al-Zaylaʿī gathered them, as did al-Haythamī in Majmaʿ (1/315–317); whoever wishes may look them up. All of them employ the wording “Asfirū” (pray when the sky has brightened), while a few read “Nawwūrū” (pray when there is light). Taken together, they reinforce the version we have preferred from the report of Rāfiʿ—namely, “Asfirū.”

As has already been shown, the directive does not mean to begin the prayer at first light, but rather to conclude it then. This understanding is somewhat clouded by what Ibn Abī Ḥātim recorded in al-ʿIlal (1/139, 143–144), al-Ṭayālisī (129), Ibn Abī Shaybah, Isḥāq ibn Rāhawayh in his Musnad, and al-Ṭabarānī in his Muʿjam. They transmit—through Ismāʿīl ibn Ibrāhīm al-Madīnī, from Hurair ibn ʿAbd al-Raḥmān ibn Rāfiʿ ibn Khadīj, from Rāfiʿ ibn Khadīj—that the Messenger of Allah ﷺ said to Bilāl:

“Delay the dawn prayer until it is bright, so that the people can see where their arrows land.”

All the men in this chain are reliable, yet I do not think that Hurair ibn ʿAbd al-Raḥmān actually heard this report.