Alqama and Aswad sought permission to enter upon Abdullah, and we had already been sitting at his door for a long time. The servant girl came out and asked permission for them, and he granted them entry. Then he stood and prayed, placing me and him on either side of him. Afterwards he said, "This is how I saw the Messenger of Allah ﷺ do it."
حدثنا عثمان بن أبي شيبة حدثنا محمد بن فضيل عن هارون بن عنترة
استأذن علقمة والأسود على عبد الله وقد كنا أطلنا القعود على بابه فخرجت الجارية فاستأذنت لهما فأذن لهما ثم قام فصلى بيني وبينه ثم قال هكذا رأيت رسول الله ﷺ فعل
[Its isnad is hasan] Nasai narrated it, Book of Imamah, chapter "The position of the imam when there are three," etc., hadith no. 800, from the hadith of Muhammad bin Fudayl through this same chain.