It is narrated from Sayyiduna Zaid bin Khalid Al-Juhani, may Allah be pleased with him, that he said: Tonight I will definitely watch the prayer of the Messenger of Allah, peace and blessings be upon him. So I made his doorstep or the tent my pillow and began to watch. The Prophet, peace and blessings be upon him, performed two light rak‘ahs, then performed two long rak‘ahs, then performed two rak‘ahs, but they were less than the previous ones, then performed two rak‘ahs, but they were less than the previous two, then performed two rak‘ahs, these were also less than the two before them, then performed witr. In this way, these became a total of thirteen rak‘ahs.