The Messenger of Allah ﷺ said, "Whoever sleeps with grease from food on his hand without washing it and something harms him, let him blame no one but himself."
حدثنا أبو كامل وهاشم قالا حدثنا زهير حدثنا سهيل عن أبيه
قال رسول الله ﷺ من نام وفي يده غمر ولم يغسله فأصابه شيء فلا يلومن إلا نفسه
Its isnad is sahih. The imams narrated it in the chapters on foods, Abu Dawud 3/366 no. 3852, Tirmidhi 4/289 no. 1860, who said, hasan gharib, Ibn Majah 2/1096 no. 3297, and Bukhari in Adab al-Mufrad 405 no. 1225.