Sahih Muslim 2464
Sahih Muslim · Book 44: The Book of the Merits of the Companions · The Virtues Of 'Abdullah Bin Mas'ud And His Mother (RA)
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ ، حَدَّثَنَا أَبِي ، حَدَّثَنَا شُعْبَةُ ، بِهَذَا الإِسْنَادِ وَزَادَ قَالَ شُعْبَةُ بَدَأَ بِهَذَيْنِ لاَ أَدْرِي بِأَيِّهِمَا بَدَأَ .
Ubaidullah b. Mu'adh reported it on the authority of his father Shu'ba with the same chain of transmitters and he made this addition. He made a mention of these two names but I do not know whose name he mentioned first.