成唯識論述記 1.335

1.335

執此自心所變之相以為常一，不稱境故，名為執也；不稱本質，名為執者。五識亦應名為有執。

Grasping this image transformed by one's own mind as permanent and unified does not conform to the object, and is therefore called a 'grasp'; if failing to conform to the original referent were called a 'grasp', the five consciousnesses should also be called having grasps.