It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) used to pray thirteen rak'ahs at night: first eight rak'ahs, then witr, then he would sit and pray two rak'ahs, and when he wanted to go into ruku, he would stand up and then perform ruku. Then, between the adhan and the prayer of Fajr, he would pray two rak'ahs.