Sahih al-Bukhari 839, 840

It is related from Mahmud ibn ar-Rabi' that he claimed to remember the Messenger of Allah, may Allah bless him and grant him peace, and remember him spitting out a mouthful of water taken from a bucket in their house. He said, "I heard 'Itban ibn Malik al-Ansari, one of the Banu Salim, say, "I used to lead my people, the Banu Salim, in the prayer. I went to the Prophet, may Allah bless him and grant him peace, and said, "My eyesight is weak and the flood-water comes between me and the mosque of my people. I would like you to come and pray somewhere in my house so that I can use it as a mosque." He said, "I will do that, Allah willing." The next morning the Messenger of Allah, may Allah bless him and grant him peace, and Abu Bakr came to me well into the day. The Messenger of Allah, may Allah bless him and grant him peace, asked for permission to enter and I gave him permission. He did not sit down when he entered the house, but said, 'Where in your house would you like me to pray?' I pointed out to him the place where I wanted him to pray. The Messenger of Allah, may Allah bless him and grant him peace, stood and we formed rows behind him and then he said the salam and we said the salam at the same time as he said it."