《资治通鉴·唐纪·唐纪三十》
左丞相裴耀卿上疏说： 我近来与盖嘉运同班朝见，观察他的举动，确实是勇烈有余，但语气自大夸耀，恐怕难成大事。
左丞相裴耀卿上疏，以为： 臣近与嘉运同班，观其举措，诚勇烈有馀，然言气矜夸，恐难成事。
Pei Yaoqing, the left prime minister, submitted a memorial, saying, "Recently, I attended the court together with Gai Jiayun. By observing his behavior, he is brave and aggressive, yet arrogant and proud. I'm afraid that he will not be able to fulfill his duty."