The Messenger of Allah ﷺ came out, accompanied by Abu Bakr Siddiq, Umar, and some of the Bedouins, until he entered our house. I milked a sheep for him, and water from our well was poured into it. I think he said that the Prophet then drank. Abu Bakr was on his left, Umar was facing him, and on his right was an Arabi.Umar said, "Messenger of Allah, give it to Abu Bakr!"But he handed it to the Arabi and said, "Those on the right come first."Anas told us, "That is the sunnah, that is the sunnah."
حدثنا الهاشمي أنبأنا إسماعيل يعني ابن جعفر قال حدثنا عبد الله بن عبد الرحمن بن معمر بن حزم أنه سمع أنس بن مالك فذكر معناه
Its isnad is sahih. Hashimi is Abu Saeed, the freedman of Banu Hashim, whose name is Abdul-Rahman bin Abdullah bin Ubayd, and Ismail bin Jafar bin Abu Kathir, both of whom are trustworthy. The hadith has already appeared at 13446.