首楞嚴義疏注經 1.489

1.489

當，猶對也。汝目顯然，故云可見。又汝眼實可見我拳相，意欲推心，且許其眼。眼即可見，何者是心？研覈至窮，妄想須顯。

*Dang* (當) means to face. Your eyes are clearly evident, hence it says "can see." Moreover, your eyes can indeed see the form of my fist; intending to examine the mind, he temporarily grants it to the eyes. Since the eyes can see, what is the mind? Investigating to the utmost limit, false conceptualization must be revealed.