Hadith 1231 Ibn `Umar (Radhi Allahu Huma) reported: The Messenger of Allah
had two Mu'adhdhin: Bilal and Ibn Umm Maktum (Radhi Allahu Huma). The Messenger of Allah
said,
"Bilal proclaims Adhan [call to Salat (prayer)] at the end of night, so eat and drink till Ibn Umm Maktum pronounces Adhan.'' Ibn `Umar (Radhi Allahu Huma) added: And the gap between their Adhan was not more than the time spent in one's getting down and the other's climbing (the minaret). [Al-Bukhari and Muslim].
Commentary: We learn from this Hadith that in the days of the Prophet
there used to be two Mu'adhdhin and two Adhan in the morning. The first Adhan was meant to warn the people who were taking the Suhur meals that the time for the Suhur was about to finish and they should make preparation for Fajr prayer. Soon after that there was a second Adhan by another Mu'adhdhin which signified that the time for food was finished and people should attend to Salat. This practice was, however, terminated later so much so that we do not find it even in the times of the Companions of the Prophet
and that of At-Tabi`un (the successors of the Prophet's Companions) and Tabi`ut-Tabi`in (the followers of the Successors).
In any case, this practice can be revived. So far, the question of time between the two Adhan is concerned, `Ulama' have stated that after announcing the Adhan, Bilal used to be engaged in prayer, etc., and waited for the daybreak. When the time for the daybreak drew near, he would then come down and inform Ibn Umm Maktum who would then make Wudhu', and then proceed to call the Adhan at the beginning of the daybreak. (Ibn Allan).
For an explanation of this Hadith by Dr Muhammad Salah view the video included in Chapter 220 Hadith No. 1228