Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:40:19 –

He knows that which deceives the eyes and what the breasts conceal.  

He, namely, God, knows the treachery of the eyes, when it steals a glance at what is prohibited ˹for it to look at˺, and what the breasts hide — ˹what˺ the hearts ˹hide˺.
القرآن:٤٠:١٩ –

يَعْلَمُ خَائِنَةَ الْأَعْيُنِ وَمَا تُخْفِي الصُّدُورُ  

{يعلم أي الله {خائنة الأعين} بمارقتها النظر إلى محرَّم {وما تخفي الصدور} القلوب.