He based on the descriptions of materials including "Kudensho" (Orally Transmitted Words) edited by Kakunyo, and according to them, Shinran had taught the thought directly to Nyoshin, and Nyoshin taught it to Kakumyo.
論拠は、覚如がまとめたとされる『口伝抄』などの書物に、親鸞より如信に口伝が行われ、更に覚如がそれを授けられたとあることによる。