Musannaf Ibn Abi Shayba 36:498

Ibn Idris narrated to us, from Ibn Jurayj, from Muhammad ibn Ali, who said: The Prophet, may Allah bless him and grant him peace, was washed while in his shirt. Ali took charge of his lower parts, al-Fadl embraced him, and al-Abbas poured the water. He said: And al-Fadl was saying, "Ease me, you have severed my aorta; I feel something descending upon me." He said: And he was washed with water from the well of Sa'd ibn Khaythama in Quba, and it is the well that is called Bi'r Aris. He said: And by Allah, I have drunk from it and washed with it.