كتاب الإيمان
1  
The Book of Faith
(12)
Chapter: Clarifying the number of branches of faith, the best and the least of them, the virtue of modesty (Al-Haya') and the fact that it is part of faith
(12)
باب بَيَانِ عَدَدِ شُعَبِ الْإِيمَانِ وَأَفْضَلِهَا وَأَدْنَاهَا وَفَضِيلَةِ الْحَيَاءِ وَكَوْنِهِ مِنْ الْإِيمَانِ
Sahih Muslim 35 b

It is narrated on the authority of Abu Huraira that the Messenger of Allah (may peace and blessings be upon him) said:

Faith has over seventy branches or over sixty branches, the most excellent of which is the declaration that there is no god but Allah, and the humblest of which is the, removal of what is injurious from the path: and modesty is a branch of faith.
حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا جَرِيرٌ، عَنْ سُهَيْلٍ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ الإِيمَانُ بِضْعٌ وَسَبْعُونَ أَوْ بِضْعٌ وَسِتُّونَ شُعْبَةً فَأَفْضَلُهَا قَوْلُ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَدْنَاهَا إِمَاطَةُ الأَذَى عَنِ الطَّرِيقِ وَالْحَيَاءُ شُعْبَةٌ مِنَ الإِيمَانِ ‏"‏ ‏.‏
Reference : Sahih Muslim 35b
In-book reference : Book 1, Hadith 60
USC-MSA web (English) reference : Book 1, Hadith 56
  (deprecated numbering scheme)