بُلُوغُ الْمَرَامِ
Bulugh al-Maram 191
The Book of Prayer
وَعَنْ اِبْنِ عُمَرَ; { إِنَّ بِلَالاً أَذَّنَ قَبْلَ اَلْفَجْرِ, فَأَمَرَهُ اَلنَّبِيُّ - صلى الله عليه وسلم -أَنْ يَرْجِعَ, فَيُنَادِيَ: "أَلَا إِنَّ اَلْعَبْدَ نَامَ } رَوَاهُ أَبُو دَاوُدَ وَضَعَّفَهُ [1] .
Narrated Ibn 'Umar (RA): Bilal called for prayer before dawn and the Prophet (ﷺ) told him to return and announce: "Lo! the slave of Allah (i.e. Bilal) had slept (hence this mistake)". [Reported by Abu Dawud, and graded as Da'if (weak)].
Sunnah.com reference: Book 2, Hadith 53