وَعَنْ أَبِي جُحَيْفَةَ - رضى الله عنه - قَالَ: { رَأَيْتُ بِلَالاً يُؤَذِّنُ وَأَتَتَبَّعُ فَاهُ, هَاهُنَا وَهَاهُنَا, وَإِصْبَعَاهُ فِي أُذُنَيْهِ } رَوَاهُ أَحْمَدُ, وَاَلتِّرْمِذِيُّ وَصَحَّحَهُ 1 .1 - صحيح. رواه أحمد (4/308-309)، والترمذي (197)، وقال الترمذي: "حديث حسن صحيح".
Narrated Narrated Abu Juhaifa (RA):
I saw Bilal calling for prayer and I would follow (looking at) his mouth (as he turned it) this (right) side and that (left) side with his fingers in his ears.
Bilal was commanded to announce the Adhan (each phrase) twice and the Iqamah (each phrase) once except "The prayer stood ready to begin" (to be pronounced twice).