The Messenger of Allah ﷺ said, "Whoever sleeps with grease from food still on his hand and does not wash it off, then something harms him, has only himself to blame."
قال رسول الله ﷺ: من نام وفي يده غمر، ولم يغسله، فأصابه شيء، فلا يلومن إلا نفسه.
It was narrated by Abu Dawud (3852), Ibn Majah (3297), Bukhari in Adab al-Mufrad (1220), and Ahmad (7569), and Ibn Hibban graded it sahih (5521), as did Bayhaqi in Sunan (7/267), all of them from the hadith of Suhayl bin Abu Salih, from his father, from Abu Hurairah, who mentioned it. Its chain of transmission is sahih. Hafiz also graded it sahih in Fath al-Bari (9/579), saying, "Its chain meets the standard of Muslim."Amash followed Suhayl bin Abu Salih in narrating it, reporting it from Abu Salih with his chain, and from that route it was narrated by Tirmidhi (1860) and Hakim (4/137). Tirmidhi said, "This is a hasan gharib hadith, we do not know it from the hadith of Amash except through this route."Abu Hatim, in his book Al-Ilal (2202), and Daraqutni, in Al-Ilal (1972), have discussion regarding this hadith, and I have mentioned what became clear to me. Allah knows best what is correct.A copy of Suhayl bin Abu Salih's narration, from his father, from Abu Hurairah, has been obtained, and Dr. Muhammad Mustafa Azami published it in his book, Dirasat fi al-Hadith al-Nabawi.