Sunan Ibn Majah — Establishing the Prayer and the Sunnah Regarding Them — Hadith No: 804
Translation
It was narrated that Abu Sa’eed Al-Khudri said:“The Messenger of Allah (ﷺ) used to start his prayer by saying: ‘Subhanaka Allahumma wa bi hamdika, wa tabarakas-muka, wa ta’ala jadduka, wa la ilaha ghairuka (Glory and praise be to You, O Allah, blessed be Your Name and exalted be Your majesty, none has the right to be worshipped but you).”