The term “fulfillment” in the Venerable Master’s words quoted above is hon-matsu in Japanese, which is usually translated “cause and effect,” “means and the end,” etc.  The hon of hon-matsu is usually understood to mean things such as “true,” “real,” “present,” etc., but in this context points to the long period of time during which Hozo Bosatsu considered:

• What sort of Vows he should establish to truly save all sentient beings (called “vow of contemplation for five kalpas”), and
• The equally long period of time he performed religious practices to fulfill those vows (called “Vow of eons of practice”).

The matsu part of hon-matsu has meanings such as “end,” “close,” etc. It refers to the fact that the Primal Vow has been fulfilled and that therefore its salvific activity is now available ? that Amida Buddha’s Great Compassion is now constantly being directed towards us. This is referred to as “Becoming enlightened after ten kalpas” and also as “fulfillment of the Primal Vow.”

In other words, hearing the “origin and fulfillment” of Amida Buddha’s Vow is hearing the mind and heart of the Vow that was established solely to save those who are so filled with base passions that they are beyond salvation.

Further, the expression, “altogether free of doubt” points to hearing (receiving) the mind and heart of Amida Buddha’s Primal Vow just as it is. It refers to the fact that evil as we are, we are fortunate beings who will undoubtedly be born in the Pure Land (the Buddha’s realm of Enlightenment).

Finally, “That is what it means to hear,” refers to is listening to the Primal Vow without doubt. Passive listening is not true hearing. Only when listening becomes one with shinjin can it be said to be true hearing. That’s when our shinjin is determined, and when we enter the world of salvation. As already related, as Master Rennyo said, “Buddha-dharma (begins and) ends with hearing.” The way to shinjin in our Jodo-Shinshu teaching is through chomon - hearing - which includes studying the doctrines of Jodo-Shinshu.