"While at Medina we were struck with famine. Ibn Az-Zubair used to provide us with dates as our food. Ibn ʿUmar used to pass by us and say, "Don't eat two dates together at a time as the Prophet ﷺ has forbidden eating two dates together at a time (in a gathering) unless one takes the permission of one's companion brother." (Using translation from Bukhārī 2490)  

كُنَّا بِالْمَدِينَةِ فَأَصَابَتْنَا سَنَةٌ فَكَانَ ابْنُ الزُّبَيْرِ يَرْزُقُ التَّمْرَ وَكَانَ ابْنُ عُمَرَ يَمُرُّ بِنَا وَيَقُولُ لَا تُقَارِنُوا «فَإِنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنِ الْقِرَانِ إِلَّا أَنْ يَسْتَأْذِنَ الرَّجُلُ أَخَاهُ»