四明尊者教行錄 4.51

4.51

答：經中雖無，而南嶽是相似位人，以三達五眼照之，合有三字故加之。後世難輒削去也。

Answer: Although they are not in the sūtra, Nanyue was a person of the stage of resemblance; illuminating with the three penetrations and the five eyes, it was appropriate to have these three characters, and therefore he added them. Later generations should not arbitrarily excise them.