حَدَّثَنَا أَبُو كَامِلٍ حَدَّثَنَا زُهَيْرٌ حَدَّثَنَا أَبُو إِسْحَاقَ عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْأَسْوَدِ عَنِ الْأَسْوَدِ وَعَلْقَمَةَ عَنْ عَبْدِ اللَّهِ قَالَ رَأَيْتُ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُكَبِّرُ فِي كُلِّ رَفْعٍ وَوَضْعٍ وَقِيَامٍ وَقُعُودٍ وَيُسَلِّمُ عَنْ يَمِينِهِ وَعَنْ شِمَالِهِ السَّلَامُ عَلَيْكُمْ وَرَحْمَةُ اللَّهِ السَّلَامُ عَلَيْكُمْ وَرَحْمَةُ اللَّهِ حَتَّى أَرَى بَيَاضَ خَدِّهِ وَرَأَيْتُ أَبَا بَكْرٍ وَعُمَرَ يَفْعَلَانِ ذَاكَ
مسند امام احمد بن حنبل · Hadith 3736
It was narrated that 'Abdullah (RA) said: I saw the Messenger of Allah (PBUH) saying takbeer every time he raised or lowered his head (in prayer), when standing and sitting, and he said the salam to his right and to his left, as-salamu 'alaikum zva rahmatullah, as-salamu 'alaikum wa rahmatullah, until I could see the whiteness of his cheek and I saw Abu Bakr and 'Umar doing likewise.
Sanad
حَدَّثَنَا أَبُو كَامِلٍ حَدَّثَنَا زُهَيْرٌ حَدَّثَنَا أَبُو إِسْحَاقَ عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْأَسْوَدِ عَنِ الْأَسْوَدِ وَعَلْقَمَةَ عَنْ عَبْدِ اللَّهِ