涅槃經遊意 1.36

1.36

故論云：非眾生身內有佛非密，身外有亦非密，四並非密。眾生則是佛為密也。

Therefore a treatise states: "That there is a Buddha inside the body of sentient beings is not esoteric; that there is one outside the body is also not esoteric; all four are not esoteric. That sentient beings are precisely the Buddha is the esoteric [teaching]."