The Messenger of Allah ﷺ used to perform the prayers much like the prayers you perform today, except that he made them lighter. His prayer was shorter than yours. In the Fajr prayer, he would recite surah al-Waqiah and similar surahs.
كان رسول الله ﷺ يصلي الصلوات كنحو من صلاتكم التي تصلون اليوم، ولكنه كان يخفف، كانت صلاته أخف من صلاتكم، وكان يقرأ في الفجر الواقعة ونحوها من السور.
Ahmad (20995) and Tabarani (1914) both narrated it through Abdul-Razzaq, and it is found in his Musannaf (2720), where he said, Israil informed us, from Simak bin Harb, that he heard Jabir bin Samura, and he related the hadith.Ibn Khuzayma (531) and Hakim (1/240) graded it sahih through this route.I say, its chain of transmission is hasan, due to some discussion regarding Simak bin Harb, though he is "truthful."