Yoshiro Tamura, "Introduction to the Lotus Sutra", p89[The] Lotus Sutra maintains that the actual and concrete Shakyamuni is in reality a version of the eternal. That is, the eternity of Shakyamuni Buddha that is emphasized is not a truth-body behind him, but the concrete and actual Shakyamuni himself. In other words, the concrete, historical, actual Shakyamuni is the living embodiment of eternal life. His death or extinction, on the other hand, was just an expression of a convenient, temporary device.
The Buddha appears to be invisible in the teaching of chapter 16, in order to open the eyes of those who have narrow ways of thinking about being and nonbeing, and such. This is his so-called extinction. Those who have their eyes open know that the concrete and actual Shakyamuni Buddha exists eternally. This matter is summarized in lines of beautiful poetry in the verses at the end of the chapter. Kumarajiva’s translation of them begins with a phrase that has been lovingly recited from ancient times: “Since I became a buddha . . .”