Śrīmālādevī Siṃhanāda Sūtra
[T]he Dharmakāya of the Buddha has the perfection of permanence, the perfection of pleasure, the perfection of self, the perfection of purity. Whatever sentient beings see the Dharmakāya of the Tathagāta that way, see correctly. Whoever see correctly are called the sons of the Lord born from his heart, born from his mouth, born from the Dharma, who behave as manifestation of Dharma and as heirs of Dharma.
The scripture, which was extremely influential by way of clarification of the Tathagātagarbha view of Śūnyatā, insists that the ultimately correct understanding of emptiness is that the Tathāgatagarbha is empty of all knowledge that is not liberation, whereas, in contrast, the qualities which characterise a Buddha are not empty of inconceivable virtues. An alternative title offered by the Buddha for this sutra expresses this idea of an ultimate meaning to the emptiness doctrine: "The True Revelation of the Buddha's Intention when Teaching Emptiness."
The sūtra has, furthermore, significantly contributed to the Mahāyāna notion of the permanent, steadfast and eternal Tathagātagarbha, which is nothing less than the perfect Dharmakāya temporarily concealed by (ultimately unreal) mental contaminants.
There is some debate as to whether or not the Tathagātagarbha constitutes true self or not, but this is explicitly refuted in the text: