Mishkat al-Masabih 1197
Prayer
Prayer at Night - Section 1
Zaid b. Khalid al-Juhani decided to watch one night what prayers God’s Messenger said. He prayed two short rak'as, then two long, long, long rak'as, then he prayed two rak'as which were less than the two preceding, then he prayed two rak'as which were less then the two preceding, then he prayed two rak'as which were less than the two preceding, then he prayed two rak'as which were less than the two preceding, then he prayed a single one, making a total of thirteen. Muslim transmitted it. The words “then he prayed two rak'as which were less than the two preceding”, mentioned four times, occur thus in Muslim’s Sahih and among those peculiar or him in Humaidi’s book, also in Malik’s Muwatta’, Abu Dawud’s Sunan, and Jami’ al-Usul.