beggar belief
To defy attempts at description; to be difficult or impossible to describe or explain. The spectacular vista at the Grand Canyon beggars belief. My boss's incompetence is astounding. It truly beggars all belief.
beggar belief (or description)
be too extraordinary to be believed (or described).beggar beˈlief/deˈscription
be too strange and unusual to be believed/described: It beggars belief that no one knew she was stealing money for so long.The sight of him completely covered with mud and oil beggared description.