Abu Hurairah reported,
The Messenger of Allah ﷺ said, "Allah's anger is most severe against a man whom His prophet killed." Rawh's version says, "whom the Messenger of Allah killed. And Allah's anger is most severe against a man who calls himself King of Kings, for there is no king except Allah 
."
Ahmad 10384
Sahihحدثنا محمد بن جعفر وروح قالا حدثنا عوف عن خلاس
عن أبي هريرة قال
قال رسول الله ﷺ اشتد غضب الله عز وجل على رجل قتله نبيه وقال روح قتله رسول الله واشتد غضب الله على رجل تسمى بملك الأملاك لا ملك إلا لله عز وجل
No references are available.
Its chain of transmission is sahih. Bukhari narrated it, 7/372, no. 4073, Fath, in the book of military expeditions, chapter on the wounds the Prophet ﷺ suffered, and Muslim narrated something similar in jihad, chapter on the intensity of Allah's anger against one whom the Messenger of Allah killed, 3/1417, no. 1793.