The Eternal and Annihilatory Nature of Tathāgatagarbha

The permanence of the tathāgatagarbha of sentient beings means that the tathāgatagarbha itself neither arises nor ceases and does not undergo change or variation. The impermanence of the tathāgatagarbha of sentient beings means that the karmic seeds contained within the tathāgatagarbha must constantly arise, cease, and change, and the consciousness-seeds of the tathāgatagarbha itself must also arise moment by moment, so as to form the continuous and unbroken functioning of the tathāgatagarbha.

Taken together, the tathāgatagarbha is neither permanent nor impermanent.