عَنِ ابْنِ عُمَرَ رَضِيَ اللَّهُ عَنْهُمَا قَالَ نَهَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَنْ يَتَنَاجَى اثْنَانِ دُونَ الثَّالِثِ إِذَا لَمْ يَكُنْ مَعَهُمْ غَيْرُهُمْ قَالَ وَنَهَى النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَنْ يُخَالِفَ الرَّجُلُ الرَّجُلَ فِي مَجْلِسِهِ وَقَالَ إِذَا رَجَعَ فَهُوَ أَحَقُّ بِهِ
It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) forbade that two people should engage in a whispering conversation leaving out a third, when there is no one else with them. Also, the Prophet (peace and blessings be upon him) forbade sitting in the place of a person who has temporarily left a gathering. Regarding this, the Prophet (peace and blessings be upon him) said: When such a person returns, he is more entitled to that place.