Zaid b Khalid al-Juhani said: I would definitely watch at night the prayer observed by the Messenger of Allah ﷺ . He prayed two short rakahs, then two long, long, long rakahs, then he prayed two rakahs which were shorter than the two preceding rakahs, then he prayed two rakahs which were shorter than the two preceding, then he prayed two rakahs which were shorter than the two preceding, then observed a single one (Witr), making a total of thirteen rakahs