When the Prophet (ﷺ) started to pray he would say: "Subhanakallahumma, wa bihamdika tabarakasmuka wa ta'ala jadduka wa la ilaha ghairuk (Glory and praise be to You, O Allah. Blessed be Your name and exalted be Your majesty, there is none worthy of worship except You.)"
Sunan an-Nasa'i Book 11, Hadith 24
← Previous Hadith When the Messenger of Allah (ﷺ) stood to offer a voluntary prayer he would say: " Allahu Akbar Wajahtu wajhi lilladhi fataras-samawatiwal-arda hanifan musliman wa ma ana minal-mushrikin. Inna salati wa nusuki wa mahyaya wa mamati lillahi rabbil-alamin, la sharika lahu, wa bidhalika umirtu wa ana awwalul-muslimin. Allahumma antal-maliku la ilaha illa anta subhanaka wa bihamdik (Allah is Most Great. Verily, I have turned my face toward Him who created the Heavens and the Earth hanifa (worhsipping none but Allah Alone), as a Muslim, and I am not of the idolaters. Verily, my Salah, my sacrifice, my living, and my dying are for Allah, the Lord of the all that exists. He has no partner. And of this I have been commanded, and I am the first of the Muslims. O Allah, You are the Sovereign and there is none worthy of worship but You, glory and praise be to You.)" Then he would recite.

Sunan an-Nasa'i Book 11, Hadith 23 Next Hadith → "When the Messenger of Allah (ﷺ) started to pray, he would say: 'Subhanakallahumma, wa bihamdika tabarakasmuka wa ta'ala jadduka wa la ilaha ghairuk (Glory and praise be to You, O Allah. Blessed be Your name and exalted be Your majesty, there is none worthy of worship except You.)"

Sunan an-Nasa'i Book 11, Hadith 25