Daily Hadith Wed 04-Aug-2021 - 25 Dhul-Hijjah 1442 حديث اليوم
Prohibition of gazing at women and Beardless Handsome Boys except in Exigency
Abu Hurairah (May Allah be pleased with him) said: The Prophet (PBUH) said, "Allah has written the very portion of Zina which a man will indulge in. There will be no escape from it. The Zina of the eye is the (lustful) look, the Zina of the ears is the listening (to voluptuous songs or talk), the Zina of the tongue is (the licentious) speech, the Zina of the hand is the (lustful) grip, the Zina of the feet is the walking (to the place where he intends to commit Zina), the heart yearns and desires and the private parts approve all that or disapprove it."[Al-Bukhari and Muslim].
This is the wording in Muslim; Al-Bukhari wording is a bit short.

Seeing, listening, walking, etc., are means of committing the sin of fornication and adultery, but they have been termed so metaphorically so that every Muslim saves himself from them. If he does not try to save himself from them, his desires will find support from the private parts of his body; that is, he will incline to immoral acts. If he keeps himself away from the means of fornication and adultery, his private parts will crush his desires, that is to say he will be saved from immoral acts. This is the reason it is said that one should avoid glances, smiles, salutation, conversation, promises and then meetings which occur by stages on one's way to fornication and adultery.

290/1622 - Riyad Us-Saliheen (Gardens of the Righteous)
باب تحريم النظر إلى المرأة الأجنبية
والأمرد الحسن لغير حاجة شرعية
وَعَنْ أبي هُريْرةَ رضي اللَّه عنْهُ عنِ النبي صَلّى اللهُ عَلَيْهِ وسَلَّم قَال : «كُتِبَ على ابْنِ آدم نَصِيبُهُ مِنَ الزِّنَا مُدْرِكٌ ذلكَ لا محالَةَ : الْعَيْنَانِ زِنَاهُمَا النَّظَرُ ، والأُذُنَانِ زِنَاهُما الاستِماعُ ، واللِّسَانُ زِنَاهُ الْكَلامُ ، وَالْيدُ زِنَاهَا الْبَطْشُ ، والرَّجْلُ زِنَاهَا الخُطَا ، والْقَلْب يَهْوَى وَيَتَمنَّى ، ويُصَدِّقُ ذلكَ الْفرْجُ أوْ يُكَذِّبُهُ » .متفقٌ عليه . وهذا لَفْظُ مسلمٍ ، وروايةُ الْبُخاريِّ مُخْتَصَرَةٌ .
1622/290 - رياض الصالحين
Wed 04-Aug-2021 - 25 Dhul-Hijjah 1442