كتاب فضائل الصحابة رضى الله تعالى عنهم
44  
The Book of the Merits of the Companions
(22)
Chapter: The Virtues Of 'Abdullah Bin Mas'ud And His Mother (RA)
(22)
باب مِنْ فَضَائِلِ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ وَأُمِّهِ رَضِيَ اللَّهُ تَعَالَى عَنْهُمَا ‏‏
Sahih Muslim 2464 f

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.

حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، بِهَذَا الإِسْنَادِ وَزَادَ قَالَ شُعْبَةُ بَدَأَ بِهَذَيْنِ لاَ أَدْرِي بِأَيِّهِمَا بَدَأَ ‏.‏
Reference : Sahih Muslim 2464f
In-book reference : Book 44, Hadith 169
USC-MSA web (English) reference : Book 31, Hadith 6028
  (deprecated numbering scheme)