It was narrated from Salim, from his father, that:

The Messenger of Allah ﷺ passed by a man who was censuring his brother about modesty. He said: "Let him be, for modesty is part of faith."

أَخْبَرَنَا هَارُونُ بْنُ عَبْدِ اللَّهِ قَالَ حَدَّثَنَا مَعْنٌ قَالَ حَدَّثَنَا مَالِكٌ ح وَالْحَارِثُ بْنُ مِسْكِينٍ قِرَاءَةً عَلَيْهِ وَأَنَا أَسْمَعُ عَنْ ابْنِ الْقَاسِمِ أَخْبَرَنِي مَالِكٌ وَاللَّفْظُ لَهُ عَنْ ابْنِ شِهَابٍ عَنْ سَالِمٍ عَنْ أَبِيهِ أَنَّ رَسُولَ اللَّهِ ﷺ مَرَّ عَلَى رَجُلٍ يَعِظُ أَخَاهُ فِي الْحَيَاءِ فَقَالَ دَعْهُ فَإِنَّ الْحَيَاءَ مِنْ الْإِيمَانِ