كتاب اللباس والزينة
37  
The Book of Clothes and Adornment
(6)
Chapter: Humility In Dress And Sticking To Coarse And Simple Clothes, Furnishings Etc., Permissibility Of Wearing Clothes Made From Camel Hair And Those On Which There Are Markings
(6)
بَاب التَّوَاضُعِ فِي اللِّبَاسِ وَالِاقْتِصَارِ عَلَى الْغَلِيظِ مِنْهُ وَالْيَسِيرِ فِي اللِّبَاسِ وَالْفِرَاشِ وَغَيْرِهِمَا
Sahih Muslim 2080 c

This hadith has been reported on the authority of Ayyub with a slight variation of wording.

وَحَدَّثَنِي مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، أَخْبَرَنَا مَعْمَرٌ، عَنْ أَيُّوبَ، بِهَذَا الإِسْنَادِ مِثْلَهُ وَقَالَ إِزَارًا غَلِيظًا ‏.‏
Reference : Sahih Muslim 2080c
In-book reference : Book 37, Hadith 59
USC-MSA web (English) reference : Book 24, Hadith 5183
  (deprecated numbering scheme)