The Messenger of Allah ﷺ ate from a shoulder of meat, then Bilal came to him, so he went out to prayer without touching water.
أن رسول الله ﷺ أكل كتفا، فجاءه بلال، فخرج إلى الصلاة، ولم يمس ماء.
Nasai (182) and Ibn Majah (491) both narrated it from the hadith of Jafar bin Muhammad, from his father, from Ali bin Husayn, from Zaynab bint Umm Salama, from Umm Salama, and he related the hadith. Its isnad is sahih, and Ibn Khuzayma (44) graded it sahih from this route.Tirmidhi (1829) narrated it through another route, from Hajjaj bin Muhammad, who said, Ibn Jurayj said, Muhammad bin Yusuf informed me that Ata bin Yasar informed him that Umm Salama informed him that she brought a roasted shoulder of meat to the Messenger of Allah ﷺ, and he ate from it, then got up for prayer without performing wudu. Tirmidhi said, hasan sahih gharib from this route.Nasai (183) narrated it through the route of Ibn Jurayj, from Muhammad bin Yusuf, from Sulayman bin Yasar, who said, I went in to see Umm Salama, and she told me that the Messenger of Allah ﷺ used to wake up in a state of janaba without having had a nocturnal emission, and then he would fast. And along with this hadith she also told him that she had brought food to the Prophet ﷺ, and he related the hadith.The hadith has other routes in Musnad Imam Ahmad and elsewhere, from Umm Salama.