I was with Abdullah bin Umar near the house of Khalid bin Uqba in the market when a man came wanting to speak with him privately. There was no one with Abdullah bin Umar except me and the man who wanted to speak with him privately. So Abdullah bin Umar called over another man, until we were four. Then he said to me and to the man he had called, "Step back a little, for I heard the Messenger of Allah ﷺ say, 'Two must not converse privately to the exclusion of a third.'"
حدثني مالك
كنت أنا وعبد الله بن عمر عند دار خالد بن عقبة التي بالسوق فجاء رجل يريد أن يناجيه وليس مع عبد الله بن عمر أحد غيري وغير الرجل الذي يريد أن يناجيه فدعا عبد الله بن عمر رجلا آخر حتى كنا أربعة فقال لي وللرجل الذي دعاه استأخرا شيئا فإني سمعت رسول الله ﷺ يقول لا يتناجى اثنان دون واحد