Musannaf Ibn Abi Shaybah

Hazrat Khubaib bin Abdur Rahman narrates that I heard from my paternal aunt, who had performed Hajj with the Messenger of Allah (peace and blessings be upon him), that the Messenger of Allah (peace and blessings be upon him) said: "When Ibn Umm Maktum gives the call to prayer at night, you may continue eating and drinking until Bilal gives the call to prayer. If Bilal gives the call to prayer at night, you may continue eating and drinking until Ibn Umm Maktum gives the call to prayer." She says that one of these two muezzins would ascend the minaret while the other would descend. We used to say to them, "Whatever you do, we will eat the pre-dawn meal (suhoor)."