Sahih al-Bukhari 819

Narrated Abu Qilaba: Once Malik bin Huwairith said to his friends, "Shall I show you how Allah's Messenger (ﷺ) used to offer hisprayers?" And it was not the time for any of the compulsory congregational prayers. So he stood up(for the prayer) bowed and said the Takbir, then he raised his head and remained standing for a whileand then prostrated and raised his head for a while (sat up for a while). He prayed like our Sheikh`Amr Ibn Salama. (Aiyub said, "The latter used to do a thing which I did not see the people doing i.e.he used to sit between the third and the fourth rak`a). Malik bin Huwairith said, "We came to theProphet (after embracing Islam) and stayed with him. He said to us, 'When you go back to yourfamilies, pray such and such a prayer at such and such a time, pray such and such a prayer at such andsuch a time, and when there is the time for the prayer then only of you should pronounce the Adhanfor the prayer and the oldest of you should lead the prayer."