عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ يُصَلِّي مِنَ اللَّيْلِ ثَمَانِيَ رَكَعَاتٍ وَيُوْتِرُ بِثَلَاثٍ وَيُصَلِّي رَكْعَتَيْنِ (وَفِي رِوَايَةٍ وَيُصَلِّي رَكْعَتَيِ الْفَجْرِ) فَلَمَّا كَبِرَ صَارَ إِلَى تِسْعٍ، سِتٍّ وَثَلَاثٍ
Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) used to offer eight units of prayer at night and three witr, after which he would offer the two sunnah of Fajr. Then, when the Messenger of Allah (peace and blessings be upon him) became advanced in age, his night prayer became nine units, that is, six units and three witr.