It was narrated that Abu Ishaq said: “I came to Al-Aswad bin Yazid, who was a close friend of mine, and said: ‘Abu ‘Amr, tell me what the Mother of the Believers told you about the prayer of the Messenger of Allah صلی اللہ علیہ وآلہ وسلم He said: She said: ‘He used to sleep for the first part of the night and stay up for the latter part.” (Sahih)