It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) would come home after offering the Isha prayer, then he would offer two rak'ahs, after that he would offer two more rak'ahs which were longer than the previous ones, then he would offer three witr and would not separate them. Then he would offer two rak'ahs sitting. In these, he would perform ruku' while sitting and would go into prostration while sitting.