Emerald Buddha and heart Sutra

Wondering why the Heart Sutra is chanted to the Emerald Buddha in Thailand. I was under the impression Thai’s were basically Theravadin and thus Pali Canon traditionalist.

Is it? Do you have a citation for that?

But anyway to address the question: Thai Buddhism is officially Theravada but there’s a long history of cultural circulation around Buddhist Asia, so it’s easy to find Mahayana and even Tantric influences in Thai Buddhist practices. And while the Pali Canon is the official Canon of Thai Buddhism, the “practical canon” includes a very wide array of other texts, including the commentaries and subcommentaries, certain Thai textbooks and traditional poems, and (yes) even some Mahayana scriptures and chants such as the Heart Sutra.