《新五代史·列传·杂传第四十二》
刘啕气量狭小、性情急躁，而李愚素来刚强耿直，动不动就连逆刘晌。
昫性褊急，而愚素刚介，动辄违戾。
Liu Han was narrow-minded and quick-tempered, while Li Yu was always strong-willed and straightforward. At the slightest provocation, Li Yu would oppose Liu Han.