Further, the Venerable Master explained the meaning of the passage at the end of the 18th Vow that states: "... those who commit the five deadly evils and abuse the right dharma are excluded." In his Songo Shinzo Meimon (Collection of Comments on the "Objects of Reverence"), he expands on this phrase in the following way:

The two kanji characters for “exclude” in the phrase, “... those who commit the
five deadly evils are excluded,” consist of the character for “just” or “only” and
the character for “except.” The purpose of the phrases, “commit five deadly
evils” and “abuse the right dharma” is to show how deeply evil such actions are,
and to declare the intent of causing birth in the Pure Land of all sentient beings in
the ten directions without exception.

Although the phrases, "commit five deadly evils" and "abuse the right dharma" are used in the 18th Vow, the Venerable Master did not understand this to mean that those who commit such acts will really be excluded from the provisions of the 18th Vow. Rather, he pointed out the deeply evil nature of these two actions, and that the purpose of the vow was to cause birth in the Pure Land of even those who commit them. If we consider that point together with the passage in the General Preface just quoted, we realize that rather than even those who "commit the five deadly evils" and "abuse the right dharma," it is precisely those who commit such acts who are the true object of "salvation."

Although the Venerable Master emphasized that the purpose of the Primal Vow is to save evil persons, he is quoted in the Epilogue of the Tannisho as saying:

When I carefully consider the Vow which Amida brought forth after five kalpas
contemplation, I find that it was for me, Shinran, alone! How grateful I am to
Amida’s Primal Vow that was created solely to save me, possessed of as many
karmic evils as I am!

As indicated above, the Venerable Master looked into the Primal Vow that was established to save "evil persons" such as those who commit the "five deadly evils," "abusers of the right dharma" and the Issendai, and looking deeply into himself, realized that he himself was the most evil of all, and thus the most in need of such a vow.