The Remaining Karmic Seeds in the Tathagatagarbha After an Arhat's Nirvana

Because Arhats have eradicated self-attachment, they no longer cling to the dharmas of the Triple Realm. With the complete extinction of a single thought of ignorance, when their karmic connections with the Triple Realm cease, they enter Nirvana and will not be reborn within the Triple Realm. As for the notion that Arhats will later emerge from Nirvana, this occurs because they have been imbued with the Mahayana Dharma; it is the maturation of the seeds of the Mahayana Dharma, not the maturation of seeds related to the dharmas of the Triple Realm. Arhats will not be reborn in the Triple Realm due to the seeds of its dharmas.

At the moment an Arhat enters Nirvana, do seeds of the Triple Realm's dharmas still exist? Seeds possess the potential to produce. If seeds exist, they must inevitably manifest. Yet Arhats no longer manifest the seeds of the Triple Realm. Where, then, do the seeds of the Triple Realm go?

The formation of seeds arises from ignorance and volitional power. Since Arhats have eliminated the single thought of ignorance, they no longer form seeds related to the Triple Realm. Furthermore, lacking volitional power, they also do not form seeds related to the Triple Realm. According to the Twelve Links of Dependent Origination, ignorance gives rise to formations (saṅkhāra). These formations encompass all activities of body, speech, and mind within the Triple Realm. Without ignorance, the formations of the Triple Realm inevitably vanish, and thus there is no further birth of the five-aggregate body. The Mahayana Dharma with which Arhats were imbued before Nirvana becomes seeds deposited within the mind-ground (citta). Their slightest fondness and joy towards the Mahayana Dharma also become seeds, capable of facilitating the maturation of the conditions for the Mahayana Dharma seeds. The greater their fondness and joy, the more easily the conditions mature, and the sooner they mature, the sooner the Arhat emerges from the state of Nirvana to take rebirth again.

Before entering Nirvana, because the manas (ego-mind) no longer clings, Arhats store the seeds of the Mahayana Dharma in the "USB drive" (the Tathāgatagarbha, Buddha-nature). When they are reborn in a future life, it is the maturation of the seeds within this "USB drive" (Tathāgatagarbha) that induces the manifestation of the five-aggregate world.