Modesty is part of faith
‘Abdullāh ibn ‘Umar (may Allah be pleased with him) reported:
The Prophet (may Allah's peace and blessings be upon him) heard a man preaching to his brother about modesty; he said: "Modesty is part of faith."
سَمِعَ النَّبِيُّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ رَجُلًا يَعِظُ أَخَاهُ فِي الْحَيَاءِ، فَقَالَ: «الْحَيَاءُ مِنَ الْإِيمَانِ».
The Prophet (may Allah's peace and blessings be upon him) heard a man advising his brother to refrain from excessive modesty, and he clarified to him that modesty is part of faith and brings nothing but good. Modesty is a noble manner that prompts one to do what is good and refrain from detestable things.
...:
What prevents one from doing good is not called modesty; rather, it is shyness, helplessness, weakness, and cowardice.
Modesty towards Allah Almighty is to carry out His commands and shun His prohibitions.
Modesty towards people means respecting and treating them in the way they deserve and avoiding things usually regarded as reprehensible.
Sahīh Al-Bukhāri (1/ 14) (24).
Sahīh Muslim (1/ 63) (36).
More (8)
توضيح الأحكام من بلوغ المرام.
للبسام (7/ 489).
منحة العلام في شرح بلوغ المرام.
لعبد الله الفوزان (10/ 330).
فتح ذي الجلال والإكرام.
لابن عثيمين (6/ 427).
سبل السلام بشرح بلوغ المرام.
للصنعاني (2/ 689).