Jami` at-Tirmidhi 598
Asim bin Damrah said:
"We asked Ali about the prayer of the Messenger of Allah during the day. He said: 'You will not be able to do that.' We said: 'Whoever among is able (he will)?' So he said: 'When the sun appeared over there (east) like it appears here (west) at Asr, the Messenger of Allah would pray two Rak'ah, and when the sun appeared over there (east) like it appears here (west) at Zuhr, he would pray four Rak'ah. And he would pray four before Zuhr and two after it, and four before Asr separating between every two Rak'ah with At-Taslim upon the angels that are close (to Allah) and those who follow them among the believers, and the Muslims."
حَدَّثَنَا مَحْمُودُ بْنُ غَيْلاَنَ، حَدَّثَنَا وَهْبُ بْنُ جَرِيرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَاصِمِ بْنِ ضَمْرَةَ، قَالَ سَأَلْنَا عَلِيًّا عَنْ صَلاَةِ، رَسُولِ اللَّهِ صلى الله عليه وسلم مِنَ النَّهَارِ فَقَالَ إِنَّكُمْ لاَ تُطِيقُونَ ذَاكَ ‏.‏ فَقُلْنَا مَنْ أَطَاقَ ذَاكَ مِنَّا ‏.‏ فَقَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِذَا كَانَتِ الشَّمْسُ مِنْ هَا هُنَا كَهَيْئَتِهَا مِنْ هَا هُنَا عِنْدَ الْعَصْرِ صَلَّى رَكْعَتَيْنِ وَإِذَا كَانَتِ الشَّمْسُ مِنْ هَا هُنَا كَهَيْئَتِهَا مِنْ هَا هُنَا عِنْدَ الظُّهْرِ صَلَّى أَرْبَعًا وَصَلَّى أَرْبَعًا قَبْلَ الظُّهْرِ وَبَعْدَهَا رَكْعَتَيْنِ وَقَبْلَ الْعَصْرِ أَرْبَعًا يَفْصِلُ بَيْنَ كُلِّ رَكْعَتَيْنِ بِالتَّسْلِيمِ عَلَى الْمَلاَئِكَةِ الْمُقَرَّبِينَ وَالنَّبِيِّينَ وَالْمُرْسَلِينَ وَمَنْ تَبِعَهُمْ مِنَ الْمُؤْمِنِينَ وَالْمُسْلِمِينَ ‏.‏