THE SUNAN AND REGULATIONS OF WUDU
Hadrat Abu Haurairah (Radi Allaahu Ta’ala Anhu) narrated that the Messenger of ALLAH said: O Abu Hurairah! When you perform ablution, say Bismillah -Wal- Hamdo Lillah (The result would be that) so long as this ablution would continue (i.e. one would remain in a state of purity), the Kiramun Katibeen (recording angles) would continue to write good deeds in his name. [Mu’jim Sagir - Tabarani, Ma’rif -ul- Hadis]