Opening Supplication in Salaat
When the Messenger of Allah would start his Salãt he would be silent for a moment before beginning to recite. So Abu Hurayra said: O' Messenger of Allah! With my father, and my mother [I would sacrifice them for you], you know your silence between the takbeer and the recitation, what are you saying [during it]? He said: I say: 'Allãhumma bã`id baynee wa bayna khatãyãya kamã bã`adta bayna 'almashriqi wal-maghribi, 'allãhumma naqqinee min khatayãyã kamã yunaqqã 'ath-thawbul 'abyadhu min 'addanasi, 'allãhumma 'ighsilnee min khatãyãya bith-thalji wal-mã'i wal-baradi O' my 'ilãh make distance between myself and my wrong-doings as You have made distance between the East and the West, O' my 'ilah purify me of my wrong-doings as a white garment is purified of dirt, O' my 'ilãh wash me of my wrong-doings with snow, water, and hail.
Agreed upon by Bukhari and Muslim, and Al-Albãni included this hadeeth in The Authentic of Good Sayings as #61.