It is narrated from Hazrat Aisha (may Allah be pleased with her) that at first, the Prophet (peace and blessings be upon him) would not perform any part of the night prayer sitting, but when the blessed body of the Prophet (peace and blessings be upon him) became heavy, he would perform as much of the prayer sitting as Allah willed. And when thirty or forty verses of the surah remained, he would stand up, recite them, and then go into prostration.