金師子章雲間類解 1.47

1.47

謂妄情於我及一切法周遍計度，一一執為實有。如癡孩，鏡中見人面像，執為有命質礙肉骨等，故云情有也。

This means that deluded conceptualization universally calculates regarding the self and all dharmas, grasping each as truly existent. Like a foolish child seeing a human face in a mirror and grasping it as having life, obstructive matter, flesh, and bones, it is therefore called "existent in conceptualization".