Authentic Supplication Number 75.
It is reported by way of ‘A’ishata, Abi Sa’eed, and others: That when the Prophet would start his salat he would say: Subhanaka ‘allahumma wa bihamdika, wa tabaraka ‘ismuka, wa ta`ala jadduka, wa la ‘ilaha ghayruka (90).
(90) I honor Allah from all things unsuitable to Him and I am in celebration of his Praise, blessed is your Name, Exalted is your Greatness, and there is no ‘ilah besides You.
Reported by At-Tirmithi, Abu Dawood, An-Nisa’ee, and Ibn Majah. Al-Albani showed it to be sound in his Al-Manar (#334). Al-Albani included this hadeeth in The Authentic of Good Sayings as #63.