When the Prophet ﷺ began the prayer, he would say, "Glory be to You, Allah, and praise be to You. Blessed is Your name, exalted is Your majesty, and there is no god but You."
حدثنا الحسن بن عرفة ويحيى بن موسى قالا حدثنا أبو معاوية عن حارثة بن أبي الرجال عن عمرة
كان النبي ﷺ إذا افتتح الصلاة قال سبحانك اللهم وبحمدك وتبارك اسمك وتعالى جدك ولا إله غيرك
Hasan. Ibn Majah also narrated it in Iqamat al-Salawat, chapter on opening the prayer, no. 806, from the hadith of Abu Muawiya al-Darir, with the same wording, and Ibn Khuzayma criticized it, no. 470, but the preceding hadith serves as a corroborating witness for it.