In general when we look at sutras we see three ways in which they can be taught. The text of “The Heart Sutra” contains all three types.
(a) Words spoken directly by the Buddha. The paragraph below includes “Transcendent Victor … said this …” indicating that these are the Buddha’s own words.
Transcendent Victor rose from that samadhi and, commending the Bodhisattva, the Mahasattva, the Superior Avalokiteshvara, said this: “Well done, well done, son of the lineage. It is just so. It is like that. One should practice the profound perfection of wisdom just as you have indicated. Even the tathagatas admire this.”
(b) Words inspired by the Buddha but not spoken by him are represented by the dialogue between Shariputra and Avalokiteshvara. Geshe Ngawang Dakpa [iv] [pg.56] states that this constitutes the body of the teaching are words inspired by the Buddha. They are words spoken by others but are spoken only though the power and inspiration of the Buddha.
(c) Words neither spoken by him nor inspired by him, but they are given with his approval. Geshe Ngawang Dakpa [iv] [pg.56] states how the Buddha allows the compiler of the sutras to contextualize them by giving brief prologues and epilogues, and by giving different statements within a sutra to contextualize it. In “The Heart Sutra” contains phrases such as “and then Shariputra asked” or “and then Avalokiteshvara responded”.
[i] “Essence of the Heart Sutra” by His Holiness the IVX Dalai Lama published by Wisdom Pulications (2015).
[ii] “The Heart Sutra Explained” by Donald S. Lopez, published by Sri Satguru Publications (1990).
[iii] “Commentary on the Heart Sutra, Jewel Light Illuminating the Meaning” by Tendar Lharampa published by FPMT Education Department (2005).
[iv] “The Heart Sutra Commentary” by Geshe Ngawang Dakpa at Tse Chen Ling, published by FPMT Education Department (2001).