The Prophet ﷺ said, "When three people are together, two should not converse privately to the exclusion of the third, and none of you should make his brother get up from his seat in order to sit in his place."
حدثنا علي بن عياش حدثنا شعيب بن أبي حمزة عن نافع
عن النبي ﷺ قال إذا اجتمع ثلاثة فلا يتناجى اثنان دون الثالث ولا يقيمن أحدكم أخاه من مجلسه ثم يجلس فيه
Its isnad is sahih. Ali bin Ayyash Alhani Himsi Bakkaa, trustworthy, one of the teachers of Ahmad. Daraqutni said, trustworthy and authoritative. Ibn Abu Hatim recorded his biography in Jarh wa Tadil 1/3/199.Ayyash, with a plain ain, a ya with two dots below, and a shin with a dot. Alhani, with a fatha on the hamza, a relation to the tribe of Alhan bin Malik, who were the brothers of Hamdan. Bakkaa, with a fatha on the ba and a doubled kaf.Shuayb bin Abu Hamza, his reliability was already established at 1681, and here we add what Abu Zura said, quoting Ahmad, "I looked at the books of Shuayb and found them precisely recorded and carefully documented," and he spoke highly of him. Bukhari recorded his biography in Tarikh al-Kabir 2/223/2.This hadith is in reality two hadiths, and its meaning has already appeared divided among sahih isnads, including numbers 5501 and 5785. See also 5949.