The Messenger of Allah ﷺ said, "A woman should not have skin-to-skin contact with another woman, nor a man with another man."
قال رسول الله ﷺ: لا تباشر المرأة المرأة، ولا الرجل الرجل.
Ahmad (8318), Tabarani in Al-Saghir (653), and Tahawi in his Mushkil (3258) all reported it from the hadith of Abu Bakr, from Hisham, from Ibn Sirin, from Abu Hurairah, and he mentioned it. Its chain is hasan on account of Abu Bakr, who is Ibn Ayyash Asadi, for there is disagreement about him, but his hadith is hasan.The exception of the child and the parent has come in the hadith of Tufawi, from Abu Hurairah, reported by Ahmad (9775) and Ibn Hibban (5583), both from the hadith of Sufyan, from Jareeri, from Abu Nadra, from Tufawi, from Abu Hurairah, who said, the Messenger of Allah ﷺ said, "A man should not touch a man's bare skin, nor should a woman touch a woman's bare skin, except a child or a parent." Tufawi was dropped from the chain in Ibn Hibban's version. This addition is munkar. Tufawi is a shaykh of Abu Nadra who is not named and is not known.Abu Dawud (2174) reported something similar to it at length, saying, Musaddad narrated to us, Bishr narrated to us, Jareeri narrated to us. Another chain, Muammal narrated to us, Ismail narrated to us. Another chain, Musa narrated to us, Hammad narrated to us, all of them from Jareeri, from Abu Nadra, a shaykh from Tufawa narrated to me, who said, I stayed as a guest with Abu Hurairah in Madinah, and I never saw a man among the companions of the Messenger of Allah ﷺ more diligent, nor more attentive to a guest, than him. While I was with him one day, he was on a couch of his, with a bag containing pebbles or date stones, and beneath him was a black slave girl of his, and he was doing tasbih with them, until when what was in the bag was used up, he tossed it to her, and she gathered it and put it back in the bag, and raised it to him. He said, shall I not tell you about myself and about the Messenger of Allah ﷺ? I said, yes indeed. He said, while I was suffering from fever in the masjid, the Messenger of Allah ﷺ came and entered the masjid, and came walking until he reached me, and placed his hand on me, and said something kind to me, so I got up. He went on walking until he came to the place where he used to pray, and he turned to face them with two rows of men and one row of women behind him, or two rows of women and one row of men, and he said, "If Satan makes me forget anything of my prayer, let the men say tasbih and let the women clap." He said, so the Messenger of Allah ﷺ prayed and did not forget anything, and he said, "Stay in your places, stay in your places." Musa added, "here." Then he praised Allah and extolled Him, then said, "Now then." Then they agreed in wording again. Then he turned to the men and said, "Is there among you a man who, when he comes to his wife, closes his door on her and lets down his curtain over her, and conceals himself with Allah's concealment?" They said, yes. He said, "Then afterward he sits and says, I did such and such, I did such and such!" He said, so they fell silent. He said, then he turned to the women and said, "Is there among you one who talks about it?" They fell silent. Then a young girl knelt, Muammal said in his narration, a plump young girl, on one of her knees, and stretched herself up toward the Messenger of Allah ﷺ so that he could see her and hear her speech, and she said, O Messenger of Allah, indeed the men do talk, and the women do talk. He said, "Do you know what that is like?" He said, "It is only like a female devil meeting a male devil in the road, and he fulfills his need with her while people are watching him. Truly the perfume of men is that whose scent is apparent and whose color is not apparent, and truly the perfume of women is that whose color is apparent and whose scent is not apparent."Abu Dawud said, from this point onward I memorized it from Muammal and Musa, "No man should reach with his hand to another man, nor a woman to another woman, except to a child or a parent." And he mentioned a third case which I have forgotten, and it is in the hadith of Musaddad, but I did not master it as well as I would like. Musa said, Hammad narrated to us, from Jareeri, from Abu Nadra, from Tufawi.Imam Ahmad (10977) reported from Ismail bin Ibrahim, from Saeed Jariri, from Abu Nadra, from a man from Tufawa, who said, I came to stay with Abu Hurairah, and he mentioned something similar to it at length. Tirmidhi (2787) and Nasai (5117, 5118) reported part of it through the route of Sufyan, from Jareeri, from Abu Nadra, from a man, from Abu Hurairah, and in one of the two narrations in Nasai it is "from Tufawi, from Abu Hurairah" in brief form. Tirmidhi said, "This hadith is hasan, except that we do not know Tufawi other than in this hadith, and we do not know his name, and the hadith of Ismail bin Ibrahim is more complete and longer."I say, perhaps he graded it hasan because of the existence of sahih corroborating narrations for some of its parts, otherwise it contains Tufawi, whom neither he nor anyone else knows except in this hadith. And Jareeri is Saeed bin Iyas, whose memory became mixed up, but Sufyan heard from him before that mixing occurred.