I asked Aswad bin Yazid about what Ayesha had told him concerning the prayer of the Messenger of Allah ﷺ.She said, "He would sleep during the first part of the night and stay awake during the latter part. Then, if he had need of his wife, he would attend to that need and sleep again. When the first call to prayer came, he would spring up." By Allah, she did not say "he got up." "Then he would pour water over himself." By Allah, she did not say "he bathed," though I know well what she meant. "And if he was not in a state of major impurity, he would perform ablution as a man does for prayer, and then pray two units."
سألت الأسود بن يزيد عما حدثته عائشة عن صلاة رسول الله ﷺ، قالت: كان ينام أول الليل ويحيي آخره، ثم إن كانت له حاجة إلى أهله قضى حاجته، ثم ينام، فإذا كان عند النداء الأول قالت: وثب (ولا والله ما قالت: قام) فأفاض عليه الماء، (ولا والله ما قالت: اغتسل، وأنا أعلم ما تريد)، وإن لم يكن جنبا توضأ وضوء الرجل للصلاة، ثم صلى الركعتين.
Bukhari narrated it in the Book of Tahajjud (1146) from the hadith of Shuba, and Muslim in the Book of the Prayer of Travelers (739) from the hadith of Zuhayr Abu Khaythama, both of them from Abu Ishaq, and the wording given here is Muslim's. Ahmad narrated it (24706) from Hasan bin Musa Ashyab, who said, "Zuhayr narrated it to us," and he added to the text of the hadith, "then he slept before water touched him." The hadith scholars criticized Abu Ishaq for this, because he was known to conceal defects in his chains of transmission, so perhaps he concealed this one too, since no one else mentioned this phrase. Ahmad said, "It is not sahih."Abu Dawud said (228), after narrating from Muhammad bin Kathir, "Sufyan narrated to us, from Abu Ishaq, from Aswad, from Ayesha, who said, 'The Messenger of Allah ﷺ used to sleep in a state of major ritual impurity without touching water.' Hasan bin Ali Wasiti narrated to us, he said, I heard Yazid bin Harun say, 'This hadith is a mistake,' meaning the hadith of Abu Ishaq."Tirmidhi said (118), "More than one narrator reported from Aswad, from Ayesha, from the Prophet ﷺ, that he used to perform wudu before sleeping, and this is more sahih than the hadith of Abu Ishaq from Aswad. This hadith was narrated from Abu Ishaq by Shuba, Sufyan, and more than one other, and they consider this to be a mistake on Abu Ishaq's part."Ibn Rajab Hanbali said in Fath al-Bari (1/362), "This hadith is one that the hadith scholars of the early generations agreed in criticizing Abu Ishaq over. Among them were Ismail bin Khalid, Shuba, Yazid bin Harun, Ahmad bin Hanbal, Abu Bakr bin Abu Shayba, Muslim bin Hajjaj, Abu Bakr Athram, Juzjani, Tirmidhi, Daraqutni, and others... As for the later jurists, many of them looked only at the trustworthiness of its narrators and so assumed it to be sahih. These people assume that any hadith narrated by a trustworthy narrator is sahih, and they do not notice the subtleties of the science of hadith defects."As for Muslim, even though he narrated it through his route, he did not mention this phrase. Hafiz said in Talkhis (1/140-141), "It is as if he deliberately omitted it, because he explained its defect in Kitab Tamyiz." However, he criticized Ibn Mafawwaz when he claimed the consensus of hadith scholars that this was a mistake on Abu Ishaq's part, saying, "He was too lenient in claiming consensus, for Bayhaqi declared it sahih, and said that Abu Ishaq had made clear his hearing from Aswad in Zuhayr's narration from him, and Ibn Surayj reconciled the two reports, as reported by Hakim from Abu Walid the jurist, from him." End of quote.The form of reconciliation that Bayhaqi mentioned from Ibn Surayj is that her statement, "he does not touch water," means ghusl, while the hadith of Umar, which is explanatory, mentions wudu.I say, it is also possible to reconcile between the two by showing that both practices are permissible, because both reports are sahih, as Daraqutni said. So wudu is sahih and is preferable, and forgoing it is also sahih. Tirmidhi reported that this is the view of Saeed bin Musayab and others.The truth is that there is no contradiction between the two hadiths. The hadith of Abu Ishaq, "before water touched him," is to be understood as referring to ghusl. If it is understood as referring to forgoing wudu, then it is meant only to show that this is permissible, while wudu is preferable. In this way it becomes clear that performing wudu is sahih, and forgoing it is also sahih, and that the matter is one of choice.