The Prophet ﷺ said, "The eyes commit fornication, the hands commit fornication, the feet commit fornication, and the private parts commit fornication."
عن النبي ﷺ قال: العينان تزنيان، واليدان تزنيان، والرجلان تزنيان، والفرج يزني.
Narrated by Imam Ahmad (3912), Abu Yaala (5364), and Bazzar - Kashf Astar (1550) - all of them via Hammam bin Yahya Awdhi, who said, Asim bin Bahdala narrated to us, from Abu Duha, from Masruq, from Ibn Masud, and he related the hadith. Its isnad is hasan because of Asim bin Bahdala, for he is hasan al-hadith. Haythami mentioned it in Majmu (6/256) and said, "Ahmad, Abu Yaala, Bazzar, and Tabarani narrated it, and their isnad is jayyid."On this subject there is also a report from Anas in a long hadith narrated by Abu Dawud (4904), from Ahmad bin Salih, who said, Abdullah bin Wahb narrated to us, who said, Saeed bin Abdul-Rahman bin Abu Amya narrated to me, that Sahl bin Abu Umama told him that he and his father visited Anas bin Malik in Madinah, and he related the story, in which it says, "The eye commits zina, and the palm, the foot, the hand, the tongue, and the private part either confirm that or deny it."Abu Yaala (3694) also narrated it via Abdullah bin Wahb, with the same chain, containing some additional wording. In the isnad is Saeed bin Abdul-Rahman bin Abu Amya, from whom only two people narrated, and no one deemed him reliable except Ibn Hibban. This is why Hafiz said in Taqrib, "Acceptable," meaning when corroborated, otherwise his hadith is weak. I have not found any corroboration for him.Hafiz Haythami relied on Ibn Hibban's assessment of his reliability, saying in Majmu (6/256), "Abu Yaala narrated it, and its narrators are the narrators of the Sahih except for Saeed bin Abdul-Rahman bin Abu Amya, who is reliable." Contrary to his usual practice, he did not point out Abu Dawud's narration, and indeed it does not meet his criteria.Furthermore, the wording of the hadith is not explicitly attributed to the Prophet, except that it could be said to carry the ruling of such attribution, since something like this would not be said merely as personal opinion.