Funeral rites of Muhammad
Nahj al-Balāgha|Volume 1|Book 1|Chapter 235
ومن كلام له (عليه السلام) قاله وهو يلي غسل رسول الله (صلى الله عليه وآله) وتجهيزه
Spoken when Amīr al-mu’minīn was busy in the funeral ablution (ghusl) of the Holy Prophet and shrouding him