Hadith 163
Sayyiduna Anas (may Allah be pleased with him) says: Bilal (may Allah be pleased with him) was commanded to say the adhan in pairs and the iqamah in singles.
Hadith 164
Sayyiduna Sa’d (may Allah be pleased with him) reports: The Prophet (peace and blessings be upon him) instructed Sayyiduna Bilal (may Allah be pleased with him) that when he gives the adhan, he should place his fingers in his ears, and said: “This will raise your voice.”
Hadith 165
وَبِإِسْنَادِهِ وَبِإِسْنَادِهِ أَنَّ بِلالا كَانَ "يُؤَذِّنُ مَثْنَى مَثْنَى ، وَيَتَشَّهَدُ مُضَعَّفًا يَسْتَقْبِلُ الْقِبْلَةَ ، فَيَقُولُ : أَشْهَدُ أَنْ لا إِلَهَ إِلا اللَّهُ مَرَّتَيْنِ ، أَشْهَدُ أَنَّ مُحَمَّدًا رَسُولُ اللَّهِ مَرَّتَيْنِ ، ثُمَّ يُرَجِّعُ ، فَيَقُولُ : أَشْهَدُ أَنْ لا إِلَهَ إِلا اللَّهُ مَرَّتَيْنِ ، أَشْهَدُ أَنَّ مُحَمَّدًا رَسُولُ اللَّهِ مَرَّتَيْنِ مُسْتَقْبِلَ الْقِبْلَةِ ، ثُمَّ يَنْحَرِفُ عَنْ يَمِينِهِ ، فَيَقُولُ : حَيَّ عَلَى الصَّلاةِ مَرَّتَيْنِ ، ثُمَّ يَنْحَرِفُ عَنْ يَسَارِهِ ، فَيَقُولُ : حَيَّ عَلَى الْفَلاحِ مَرَّتَيْنِ ، ثُمَّ يَسْتَقْبِلُ الْقِبْلَةَ ، فَيَقُولُ : اللَّهُ أَكْبَرُ اللَّهُ أَكْبَرُ ، لا إِلَهَ إِلا اللَّهُ ، وَإِقَامَتُهُ مُنْفَرِدَةٌ ، قَدْ قَامَتِ الصَّلاةُ مَرَّةً وَاحِدَةً ، وَأَنَّهُ كَانَ يُؤَذِّنُ يَوْمَ الْجُمُعَةِ لِلْجُمُعَةِ عَلَى عَهْدِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا صَارَ الْفَيْءُ مثل الشِّرَاكِ "
With this same chain, it is narrated that Sayyiduna Bilal (may Allah be pleased with him) would say the words of the adhan in pairs and would recite the testimony (tashahhud) twice. When he faced the qiblah, he would say: “Ashhadu an la ilaha illallah” twice. “Ashhadu anna Muhammadan Rasulullah” twice. Then he would repeat and say, while still facing the qiblah: “Ashhadu an la ilaha illallah” twice, “Ashhadu anna Muhammadan Rasulullah” twice. Then, turning to the right, he would say: “Hayya ‘ala-s-salah” twice. Then, turning to the left, he would say: “Hayya ‘ala-l-falah” twice. Then, still facing the qiblah, he would say: “Allahu Akbar, Allahu Akbar, la ilaha illallah.” His (may Allah be pleased with him) iqamah was unique; he would say “Qad qamatis salah” once. And on the day of Jumu’ah, the adhan for Jumu’ah during the time of the Messenger of Allah (peace and blessings be upon him) would be given when the shadow became equal to the strap.