金剛經纂要刊定記 6.166

6.166

意謂下。出答意也。意云：但見法身之相好，則知相好之法身。如見草木之苗必知其根，由是科文約喻而立。

"It means..." and below presents the intent of the reply. The intent is: merely by seeing the marks and signs of the dharmakāya, one knows the dharmakāya of the marks and signs. Just as seeing the sprout of a plant or tree means one certainly knows its root, the section heading is established on the basis of this metaphor.