The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship
حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، وَابْنُ أَبِي عُمَرَ، وَعَمْرٌو النَّاقِدُ، جَمِيعًا عَنِ ابْنِ عُيَيْنَةَ، عَنِ الزُّهْرِيِّ، بِهَذَا الإِسْنَادِ وَزَادَ ابْنُ عُيَيْنَةَ " وَلاَ تَقَاطَعُوا " .This hadith has been narrated on the authority of Zuhri with the same chain of transmitters with the addition of Ibn Uyaina (and the words are):" Do not cut off (mutual relations)
From Sahih Muslim, whose reports the scholars accept as authentic.