What is the meaning of "the true mind is neither lost nor gained"?

The true mind cannot be attained, nor can it be lost. What does "neither lost nor attained" mean? It means neither arising nor ceasing. Because it does not arise, it is not attained—it exists originally; because it does not cease, there is no need for it to arise, and thus there is nothing to attain. The true mind itself is an unconditioned dharma (asaṃskṛta-dharma); there is no need to reach it. Unconditioned dharmas that are cultivated through practice still have a time of ceasing—they are conditioned dharmas subject to arising and ceasing. The suchness of true suchness (tathatā), however, neither arises nor ceases, and it accompanies the tathāgatagarbha like a shadow following a form. The tathāgatagarbha is without form and without mark; they mutually contain one another, yet even in their mutual containment there is no mark of containing—they simply do not repel one another, but cooperate with each other, jointly accomplishing all dharmas. The Buddha's tathāgatagarbha and sentient beings' tathāgatagarbha are likewise the same, cooperating with one another. Therefore, the tathāgatagarbha of sentient beings does not need to merge into the Buddha's tathāgatagarbha; the tathāgatagarbha is not material form (rūpa)—it has no inside and no outside, and cannot enter into one another. Only material forms can merge into and enter one another.