Milk mixed with water was brought to Messenger of Allah ﷺ while a bedouin was on his right and Abu Bakr was on his left. He drank (of it) and then gave (it) to the bedouin and said, 'The right" "The right (first).  

أَنَّ رَسُولَ اللَّهِ ﷺ أُتِيَ بِلَبَنٍ قَدْ شِيبَ بِمَاءٍ وَعَنْ يَمِينِهِ أَعْرَابِيٌّ وَعَنْ شِمَالِهِ أَبُو بَكْرٍ فَشَرِبَ ثُمَّ أَعْطَى الأَعْرَابِيَّ وَقَالَ الأَيْمَنَ الأَيْمَنَ