عَنْ عَاصِمِ بْنِ ضَمْرَةَ قَالَ: سُئِلَ عَلِيٌّ رَضِيَ اللَّهُ عَنْهُ عَنْ صَلَاةِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ: كَانَ يُصَلِّي مِنَ اللَّيْلِ سِتَّ عَشْرَةَ رَكْعَةً
Asim bin Damrah reports that when Sayyiduna Ali (may Allah be pleased with him) was asked about the prayer of the Messenger of Allah (peace and blessings be upon him), he said: He used to pray sixteen rak‘ahs at night.