Abu Dawud
Prayer
Book Number: 002 / Hadith Number: 1461
Narated By Umm Salamah, Ummul Mu'minin : Ya'la ibn Mumallak said that he asked Umm Salamah about the recitation and prayer of the Apostle of Allah (pbuh).
She said: What have you to do with his prayer? He would pray, then sleep as long as he had prayed, till morning. She then described his recitation and did so with an exposition word by word.