عَنْ أَبِي أُمَامَةَ الْبَاهِلِيِّ رَضِيَ اللَّهُ عَنْهُ قَالَ كَانَ نَبِيُّ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا قَامَ إِلَى الصَّلَاةِ وَفِي رِوَايَةٍ إِذَا دَخَلَ فِي الصَّلَاةِ مِنَ اللَّيْلِ كَبَّرَ ثَلَاثَ مَرَّاتٍ ثُمَّ قَالَ لَا إِلَهَ إِلَّا اللَّهُ ثَلَاثَ مَرَّاتٍ وَسُبْحَانَ اللَّهِ وَبِحَمْدِهِ ثَلَاثَ مَرَّاتٍ ثُمَّ قَالَ أَعُوذُ بِاللَّهِ مِنَ الشَّيْطَانِ الرَّجِيمِ مِنْ هَمْزِهِ وَنَفْخِهِ وَنَفْثِهِ
It is narrated from Sayyiduna Abu Umamah Bahili (may Allah be pleased with him) that when the Noble Prophet (peace and blessings be upon him) would stand for prayer at night and enter into prayer, he would say "Allahu Akbar" three times, "La ilaha illallah" three times, and "Subhanallahi wa bihamdihi" three times, then he would recite: "A‘udhu billahi minash-shaytanir-rajim min hamzihi wa nafkhihi wa nafthihi."