Authentic Supplication Number 37.

It is reported of the Prophet  that he said: “One who wakes up at night and says: La ‘ilaha ‘illa ‘allahu wahdahu la shareeka lahu, lahul mulku wa lahul hamdu, wa huwa `ala kulli shay’in qadeerun, ‘al-hamdu lil-lahi, wa subhanallahi, wa la ‘ilaha ‘illa ‘allahu, wa ‘allahu ‘akbaru, wa la hawla wa la quwwata ‘illa bil-lahi ‘al-`alyyil-`atheemi, (59) then says: ‘Allahumma ‘ighfirlee, (60) or supplicates, he will be answered, then if he makes ablution and prays his prayer would be accepted”.

Footnotes.
(59) There is no ‘ilah except Allah, Alone, no associate does He have, his is the Kingdom, to Him is all praise, and He is very able to do every thing. All praise be to Allah, Glory be Allah, there is no ‘ilah except Allah, and Allah is greater [than every thing]. There is neither might, nor strength except by Allah The High The Magnificent.

(60) O’ my ‘ilah forgive me.

Reporters.
To be found under Tahajjud in Saheeh al-Bukhari. The two words “‘al-`alyyil-`atheemi” were not in al-Bukhari’s wording, they were found with Ibn Majah, and Ibn As-Sunni with sound ascription as described by Sheikh Al-Albani. Al-Albani included this hadeeth in The Authentic of Good Sayings as #35.