Mishkat al-Masabih 1213
‘Ubada b. as-Samit reported God’s Messenger as saying, “If anyone is disturbed [from sleep] during the night and says, ‘There is no god but God alone who has no partner; to Him belongs the kingdom, to Him praise is due, and He is omnipotent; glory be to God; praise be to God; there is no god but God:
God is most great; there is no might and no power but in God,’ then says, ‘My Lord, forgive me’ (or he said, Then makes supplication), he will receive an answer; and if he performs ablution and prays, his prayer will be accepted.” 

Bukhari transmitted it.
وَعَنْ عُبَادَةَ بْنِ الصَّامِتِ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: 
" مَنْ تَعَارَّ مِنَ اللَّيْلِ فَقَالَ: لَا إِلَهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ وَسُبْحَانَ اللَّهِ وَالْحَمْدُ لِلَّهِ وَلَا إِلَهَ إِلَّا اللَّهُ وَاللَّهُ أَكْبَرُ وَلَا حَوْلَ وَلَا قُوَّةَ إِلَّا بِاللَّهِ ثُمَّ قَالَ: رَبِّ اغْفِرْ لِي أَوْ قَالَ: ثمَّ دَعَا استيجيب لَهُ فَإِنْ تَوَضَّأَ وَصَلَّى قُبِلَتْ صَلَاتُهُ " رَوَاهُ البُخَارِيّ