Musnad Ahmad 1153:1754

'Abd al-Quddus ibn Bakr narrated to us, he said: Hisham informed us, from his father, from 'Aishah, she said: The Messenger of Allah, peace and blessings of Allah be upon him, entered upon me while a woman from Banu Asad ibn Khuzaymah was with me. He said: "Who is this?" I said: "This is so-and-so, and she stands [in prayer] at night"—or she does not sleep at night. He disliked that, until I saw the dislike on his face. He said: "Take upon yourselves of the deeds that which you can bear, for Allah, the Mighty and Majestic, does not grow weary until you grow weary."