(a) It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that Sayyiduna Bilal (may Allah be pleased with him) gave the adhan before the break of dawn, so the Prophet (peace and blessings be upon him) ordered him to go back and announce: "Behold, the servant was asleep! Behold, the servant was asleep!" He said it three times. (b) In the hadith of Musa bin Isma'il: "Behold, the servant was asleep." In this hadith, Hammad bin Salamah is alone in narrating it from Ayyub with a connected chain.
It is also narrated from Sa'id bin Zarbi from Ayyub, except that Sa'id is da'if (weak). The narration of Hammad is solitary, and the hadith of Ubaydullah bin Umar from Nafi' from Ibn Umar is more authentic than it, and with it is the narration of al-Zuhri from Salim from his father.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 1797