Musnad Ahmad 1153:691

Abu Kamil narrated to us, he said: Zuhayr narrated to us, he said: Abu Ishaq narrated to us, he said: I came to al-Aswad ibn Yazid, and he was a brother or a friend to me, and I said: "O Abu ‘Amr, narrate to me what the Mother of the Believers narrated to you regarding the prayer of the Messenger of Allah, may Allah bless him and grant him peace." He said: She said: "He used to sleep during the first part of the night and keep the last part of it alive. Sometimes he would have a need for his wife, then he would sleep before touching water. Then, when the first call [to prayer] came, he would spring up—and she did not say: 'he stood up'—and he would pour water over himself—and she did not say: 'he performed ghusl,' and I know what you mean. And if he was not in a state of major ritual impurity (junub), he would perform ablution like the ablution of a man for prayer."