It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) halted with us for a night's rest when he (peace and blessings be upon him) was returning from Khaybar. He (peace and blessings be upon him) said: "Who will watch over the prayer for us?" Bilal (may Allah be pleased with him) said: I will. (During the night) they slept until the sun rose. He (peace and blessings be upon him) said: "O Bilal, did you sleep?" He said: That which took hold of your souls took hold of my soul (that is, sleep). He (peace and blessings be upon him) ordered Bilal (may Allah be pleased with him), and he gave the adhan and the iqamah. The Messenger of Allah (peace and blessings be upon him) said: "Move away from this place of yours; here heedlessness befell you." Then the Messenger of Allah (peace and blessings be upon him) said: "If any of you forgets a prayer, let him pray it when he remembers it." Allah, the Mighty and Majestic, said: "Establish the prayer for My remembrance" [Ta Ha: 14].
(b) In al-Muwatta', al-Zuhri narrated it from Ibn al-Musayyib in mursal form and mentioned the adhan in it. He also says that the adhan in this story is sahih (authentic) and established.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1894