The Prophet (ﷺ) said, "Whoever gets up at night and says:-

La ilâha illallâhu Waḥdahu la sharika lahu. Lahul-mulku, wa lahul-ḥamdu, wa Huwa 'ala kulli shai'in Qadir. Alhamdu lillâhi, wa subḥânallâhi, wa La ilâha illallâhu, wallâhu akbar, wa ḥawla walâ quwata illâ billâh

(none has the right to be worshipped but Allâh. He is the Only One Who has no partners. His is the kingdom and all the praises are for Him. He is Omnipotent. All the praises are for Allâh. All the glories are for Allâh. And none has the right to be worshipped but Allâh, and Allâh is the Most Great and there is neither might nor power except with Allah). And then says:-' Allâhumma, ighfir li (O Allâh ! Forgive me). Or invokes (Allâh), he will be responded to and if he performs ablution [and offers (prayer)], his (prayer) will be accepted." [2:253-O.B.]