This concept originates from the Vimalakirti Sutra, a foundational text in Mahayana and Zen Buddhism. The famous line states: "The straightforward mind (direct heart) is the place of practice."
Historically, this was a revolutionary idea. It told the layperson—the farmer, the artist, the parent—that they did not need to retreat to a mountain monastery to find the "Way." If they approached their work and their relationships with a sincere, "willing" heart, their kitchen, their field, or their studio became their temple. It democratized enlightenment, turning every breath into an act of cultivation.