No dharma can lie outside the tathāgatagarbha

The tathāgatagarbha gives rise to all dharmas; every single dharma is produced by the tathāgatagarbha. Not only the myriad dharmas—hundreds of millions of dharmas, immeasurable dharmas—all are produced by the tathāgatagarbha. Apart from the tathāgatagarbha, everything belongs to the dharmas among those hundreds of millions of dharmas. Whether it is empty space, the air, or the Buddha-lands of the ten directions, there is not a single dharma that can go beyond the tathāgatagarbha. The tathāgatagarbha, the eighth consciousness, is called the one true dharma realm; no dharma can go beyond this one true dharma realm. The hundreds of millions of dharmas are like Sun Wukong, while the tathāgatagarbha is like the Buddha. If one were to ask where the tathāgatagarbha comes from, the Heart Sutra and the Prajñā sūtras point out to us that the tathāgatagarbha neither comes nor goes, neither arises nor ceases; it exists from the very beginning, naturally and intrinsically so.

Since it is naturally and intrinsically so, even the Buddhas of the ten directions cannot tell us why the tathāgatagarbha has always existed from the beginning. This is not a dharma invented or created by the Buddhas; rather, it is a truth that the Buddha discovered and realized through cultivation over three countless great kalpas, and then proclaimed for sentient beings.

The Buddha also taught in the Śūraṅgama Sūtra: 「十方虚空生汝心内，如片云点泰清里。」 This clearly tells us that space is produced by the mind, and that the place it occupies within the mind is extremely tiny. Therefore, although the mind of the tathāgatagarbha is empty of any dharma, He is vast and ever vaster, boundless and ever more boundless, encompassing all phenomena and omitting not a single dharma. No matter how great one's abilities, no one can leap beyond the tathāgatagarbha.