Narrated Abu Musa Al-Ash'ari:
The Prophet used to invoke Allah, saying, "Allahumma ighfirli khati'ati wa jahli wa israfi fi amri, wa ma anta a-'lamu bihi minni. Allahumma ighfirli hazali wa jiddi wa khata'i wa amdi,...
None has the right to be worshipped but Allah alone, Who has no partner. His is the dominion and His is the praise, and He is Able to do all things. We return repentant to our Lord, worshipping our Lord, and praising...
-> Read More Info: Bukhari 7/163, Muslim 2/980. The Prophet (SAW) used to say this when returning from a campaign or from Hajj.