A teaching (yulu) from Torei Enji, 1721-1792, a disciple and successor of Hakuin.
The monks of our school do not know how to set the body at ease and be obedient to the Dharma. Nowadays they often mistake their uninteresting views for ‘Zen’. They do not peruse the sutras and treatises [shastra’s], but rather query why in a ‘special transmission outside the teachings’ sutras and treatises should be used.
In particular, they do not know that in a special transmission outside the teachings the teachings are never an impediment. Unless the special transmission outside the teachings can embrace the teachings, it is not the genuine special transmission outside the teachings.
Therefore, if the mirror is clear, there is no need to choose what images and objects to reflect. If no image appears, then the mirror is not yet completely clear. To reject images and obects is only productive of even more dust and dirt covering the mirror, and is not the seeing of the Great Way.
Indeed, the sutras have a profound meaning and purport. They point out the manifold obstacles to your seeing. Just because the seeing is not clear, one may end up disregarding the golden words of the Tathagata [Buddha] and fail to probe into the depth of those profound principles of the sutras.
(Torei, Enji: Discourse on the Inexhaustible Lamp of the Zen School.
London 1996, p. 301)