The Messenger of Allah ﷺ used to sleep on his back until he snored, then he would get up and pray without performing ablution.
أن رسول الله ﷺ كان ينام مستلقيا حتى ينفخ، ثم يقوم فيصلي ولا يتوضأ.
Abu Yaala (3570) and Bazzar (his Zawaid 2437) narrated it, both through the route of Mansur bin Abu Aswad, from Amash, from Ibrahim, from Alqama, from Abdullah, and he related it. Bazzar said, "Mansur was not corroborated on this chain, although he is a Kufan who is not problematic." I say, his being alone in narrating it does not harm it, for he is trustworthy, Ibn Main and others deemed him trustworthy.As for what Ibn Majah (475) narrated through another route, from Hajjaj, from Fudayl bin Amr, from Ibrahim with the same wording, it contains Hajjaj, who is Ibn Artaah, a truthful narrator but one who made many errors and practiced tadlis, and he narrated using "an" without an explicit statement of hearing.This may be specific to the Prophet ﷺ, given what came in the hadith of Ayesha, "His eye sleeps but his heart does not sleep," because it is mentioned in some reports that the Prophet ﷺ was not like others.As for the hadith, "The tie of the anus is the two eyes, so whoever sleeps should perform wudu," it is a daif hadith that is not established, as Ibn Arabi said.I say, Abu Dawud (203), Ibn Majah (477), and Ahmad (887) all narrated it through the route of Baqiya, from Wadeen bin Ata, from Mahfuz bin Alqama, from Abdul-Rahman bin Aaiz, from Ali bin Abu Talib, as a raised hadith.It contains several defects. The first, Baqiya bin Walid Himsi, who practiced tadlis, including the tadlis of taswiya (leveling out the chain), but an explicit statement of direct narration came in Imam Ahmad's version from his teacher Wadeen bin Ata, and the majority hold that this is sufficient.The second, Wadeen bin Ata is disputed, Ahmad and Ibn Main deemed him trustworthy, while Ibn Saad and Juzjani deemed him daif. Ibn Adi said, "I see no problem with his hadiths." Meaning, his hadith is hasan so long as no error or confusion appears from him.The third, Abdul-Rahman bin Aaiz Azdi, of whom Bukhari said, as reported by Ibn Manda, "He had companionship," though this is not correct, as stated in al-Isabah. Abu Hatim said, "Ibn Aaiz had no companionship, rather he is one of the Tabiin." Abu Zura said, "Abdul-Rahman bin Aaiz's narration from Ali is mursal." Meaning it is disconnected, because he did not hear from him.Ibn Abu Hatim said, "I asked my father about this hadith, and about the hadith of Abu Bakr bin Abu Maryam, from Atiya bin Qays, from Muawiya, from the Prophet ﷺ, 'The eye is the tie of the anus,' and he said, 'Neither of them is strong.'"Abu Zura was asked about the hadith of Ibn Aaiz, from Ali, with this hadith, and he said, "Ibn Aaiz's narration from Ali is mursal." Ilal (106).Ibn Abdul-Barr said in Tamhid (18/248), "These two hadiths are not strong." Ibn Hajar said in Bulugh Maram (no. 80) about the hadith of Ali and Muawiya, "Both chains contain daif."I say, the hadith of Muawiya was narrated by Ahmad (16879), Abu Yaala (7372), and Tabarani in al-Kabir (875), all through the route of Abu Bakr bin Abu Maryam, with this wording. Abu Bakr bin Abu Maryam is daif, his house was robbed and he became confused afterward.But Nawawi deemed it hasan in Majmu (20/2), and so did Ibn Salah, as mentioned in Badr Munir (2/432), perhaps because its meaning is sound, as it came in the hadith of Safwan bin Assal Muradi, "We would not take them off, meaning the leather socks, for defecation, urination, or sleep." Ahmad narrated it (18093), and it is documented in the chapter on wiping over leather socks.As-sah is the anal ring or the rear. Al-wikaa is the string with which a waterskin, a bag, or the like is tied.Likewise the hadith, "Wudu is only required for one who sleeps lying down," is munkar. Abu Dawud (202), Tirmidhi (77), and Ahmad (2315) all narrated it through the route of Abu Khalid Dalani, from Qatada, from Abu Aliyah, from Ibn Abbas, who related it in a long hadith. Its chain is daif because of Dalani.Abu Dawud said, "A group narrated it from him, that is from Qatada, from Ibn Abbas, and they did not mention any of this," meaning Dalani alone added this addition. Imam Ahmad criticized Dalani, saying, "What is it with Yazid Dalani, that he intrudes among the companions of Qatada?"