عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏”‏ إِذَا كُنْتُمْ ثَلاَثَةً فَلاَ يَتَنَاجَى اثْنَانِ دُونَ صَاحِبِهِمَا ‏”

Tirmidhi 2825

Narrated ‘Abdullahؓ that the Messenger of Allahﷺ said that “Whenever there are three of you, then let two not converse in exclusion of their companion.”