Musnad Ahmad 1153:177

Abu Mu'awiyah narrated to us, Hisham ibn 'Urwah narrated to us, from his father, from 'Aishah, who said: When Abu Bakr became heavy [with illness], he said: "What day is this?" We said: "Monday." He said: "And on what day was the Messenger of Allah, peace and blessings of Allah be upon him, taken?" She said: We said: "He was taken on Monday." He said: "Then I hope for what is between me and the night." She said: He was wearing a garment that had a stain of saffron on it. He said: "When I die, wash this garment of mine, and add two new garments to it, then shroud me in three garments." We said: "Shall we not make them all new?" She said: He said: "No, it is only for the pus." She said: So he died on the night of Tuesday.