Why is Prajñā-pāramitā also empty of marks?

Original text: 佛说般若波罗蜜。即非般若波罗蜜。是名般若波罗蜜。

Explanation: The Mahāyāna dharma of prajñā-pāramitā that the Buddha taught to sentient beings is not an actually existent prajñā-pāramitā; there is not really a prajñā-pāramitā. It is provisionally named prajñā-pāramitā, and its dharma-mark is also empty.

Prajñā-pāramitā is an Indian term; translated into Chinese it means "great wisdom that reaches the other shore," a metaphor for the state of nirvāṇa in which the vajra mind (Vajracitta)—or the prajñā mind-essence—has no shore of birth-and-death on this side. Both this shore and the other shore are states, provisional names, not entities, nor true reality; there is no substantial mark of a this-shore or an other-shore. Therefore prajñā-pāramitā is an empty mark, provisionally named prajñā-pāramitā. By the same token, the six pāramitās are also empty marks, without real substance, not true reality; pāramitā is a provisional name, and the six perfections likewise have no substantial essence or mark—they are empty marks of arising, ceasing, and mutation conjured forth by the vajra mind. Upon reaching the shore, one abandons the raft; after attaining buddhahood and completing cultivation, there is no longer any need to cultivate the dharma of the pāramitās.

Whatever dharmas can be established and exist only by relying on the vajra mind-essence are all conjured empty marks and false marks, without substance or an independent self-nature. The Prajñā-pāramitā Sūtra evolved from the vajra mind-essence; sentient beings rely on the prajñā-pāramitā to cultivate and thereby accomplish the buddha-path. After attaining buddhahood, one discards the Prajñā-pāramitā Sūtra, no longer needing to study or rely upon it. The appearance of the Prajñā-pāramitā Sūtra came about through the buddhas expounding it in accordance with sentient beings' ripened conditions for study and cultivation; if the conditions were not complete, the buddhas would not speak the Prajñā-pāramitā Sūtra, and this sūtra would have no cause to appear before sentient beings. Therefore the Prajñā-pāramitā Sūtra is an interpretation and annotation of the nature of the vajra mind-essence, not the vajra mind-essence itself; hence it is not true reality but a false mark. And the principles expounded in the sūtra, named prajñā-pāramitā, likewise do not represent the vajra mind-essence itself; therefore they are also not true reality but an empty mark. It is for this kind of empty mark that the name prajñā-pāramitā is given.