All Dharmas Are a Bubble in the Great Ocean of Tathāgatagarbha

The Śūraṅgama Sūtra:譬如澄清百千大海弃之，唯认一浮沤体，目为全潮，穷尽瀛渤。

The great ocean is a metaphor for the tathāgatagarbha, while the foam and bubbles of the seas are a metaphor for the myriad dharmas; all the myriad dharmas are but a single bubble within the great ocean of the tathāgatagarbha. The Buddha is telling us not to take any dharma among the five aggregates and eighteen realms as the true tathāgatagarbha, or as the self.

A body of the five aggregates is just one bubble, not the whole self. Do not let a single five-aggregate body blind your eyes so that you fail to see the entire great ocean of the tathāgatagarbha. All the dharmas within the great ocean of the tathāgatagarbha belong to oneself—not merely the present five-aggregate body and five-aggregate world, not merely the present wealth, sex, fame, food, and sleep, not merely the present world of the five desires. Therefore our vision must be broadened, so that we can see all the past lives, ages, and kalpas within the tathāgatagarbha, all the way through to the worlds after attaining buddhahood. And all these worlds are merely bubbles within the tathāgatagarbha, nothing worth clinging to. As long as we grasp the tathāgatagarbha, it is as if we possess the entire great ocean—why then would we care about a single bubble of the five aggregates?

Practicing the Buddhadharma requires grasping the essentials: take up the tathāgatagarbha as the guiding cord, and take hold of the myriad dharmas as the collar. When the cord is raised, the net opens; as long as the tathāgatagarbha is in one's mind, one can see all the myriad dharmas, gathering the hundred rivers back into the great ocean. But if one takes the five-aggregate body as the self and as real, it will be like a single leaf blocking the eye, unable to see the vast expanse of heaven and earth.