Sahih Muslim Book 4, Hadith Number 1626.

Chapter : Permissibility of observing Nafl (voluntary prayer) standing or sitting and observing some part of it standing or sitting.

Zurara b. Aufa reported that Sa’d b. Hisham was his neighbour and he informed him that he had divorced his wife and he narrated the Hadith like the one transmitted by Sa’d. She (‘Aisha) said: Who is Hisham? He said: The son of ‘Amir. She said: What a fine man he was; he participated in the Battle of Uhud along with the Messenger of Allah (may peace be upon him). Hakim b. Aflah said: If I ever knew that you do not go to ‘Aisha, I would not have informed you about her Hadith (So that you would have gone to her and heard it from her orally).