Mishkatul Masabih — Hadith #40117

He slept with the Messenger of Allah (may peace be upon him) one night. He said, Rasulullah (Sallallahu Alaihi Wasallam) woke up at night. He performed miswak and ablution. Then he recited this verse, Inna fi khalkis sama-wa-ti wal arzi..... to the end of the surah. Then he stood up, then prayed two rak'ahs. In prayer, he performed long qiyam, ruku' and sajdah. After the prayer he fell asleep and started snoring. He did this three times. He prayed six rak'at three times He paid Every time he performed miswak, ablution. He recited those verses too. He prayed the last three rak'ahs of the Witr. (Muslim) [1]