عَنْ أَبِي أَيُّوبَ الْأَنْصَارِيِّ رَضِيَ اللَّهُ عَنْهُ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ كَانَ يَسْتَاكُ مِنَ اللَّيْلِ مَرَّتَيْنِ أَوْ ثَلَاثًا وَإِذَا قَامَ يُصَلِّي مِنَ اللَّيْلِ صَلَّى أَرْبَعَ رَكَعَاتٍ لَا يَتَكَلَّمُ وَلَا يَأْمُرُ بِشَيْءٍ، وَيُسَلِّمُ بَيْنَ كُلِّ رَكْعَتَيْنِ
It is narrated from Sayyiduna Abu Ayyub Ansari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) would use the miswak two or three times at night, and when he would get up at night to pray, he would perform four rak‘ahs, in which he would neither speak nor give any command regarding anything, and after every two rak‘ahs he would say salam.