Modesty is from faith
الْحَيَاءُ مِنَ الْإِيمَانِ
Al-haya'u mina-l-iman.
"Modesty is from faith."
Narrated by Abdullah ibn Umar. Sahih al-Bukhari 24, Sahih Muslim 36
A short reflection
When haya goes, faith bleeds out with it. The Prophet ﷺ said in another hadith: if you have no haya, do as you wish. He meant the warning, not the licence.