大乘起信論廣釋卷第三．四．五 5.36

5.36

[Treatise:] Yet in reality, bodhisattvas […] asaṃkhyeya kalpas.
[Commentary:] This is the virtue of actual practice being non-distinct. "Yet in reality, bodhisattvas […]": first, this directly clarifies the meaning of equality. First, gotra is equal, because all enter the station of the bodhisattva gotra. Second, faculties are equal, because superior, middling, and inferior faculties are all the superior faculty. Third, arousing the mind is equal, because arousing the straightforward mind and so forth are all without difference. Fourth, what is realised is equal, because all realise the fundamental principle of suchness. Thus the New Treatise says: "Gotra, faculties, arousing the mind, and realization are all identical and equal." Because of these equalities, there is no dharma of surpassing.
"Because all bodhisattvas […]": next, this explains and establishes it in terms of time. From initial correct faith up to the first ground is the first incalculable kalpa; from the first ground up to the fulfillment of the seventh ground is two asaṃkhyeyas; fulfilling the eighth ground up to the final mind of the tenth ground is three asaṃkhyeya kalpas. Since all require three asaṃkhyeyas, there is no surpassing.
However, the number of an asaṃkhyeya has greater and lesser counts. According to the Hīnayāna, there are sixty numbers: counting kalpas up to a hundred thousand is the first number; thus proceeding, multiplying tenfold at each step, the fifty-second is named an asaṃkhyeya. When finished, beginning again, three asaṃkhyeyas are called three asaṃkhyeyas. According to the Mahāsāṃghika, there are one hundred and twenty numbers: counting up to a hundred thousand is called one koṭi, as the first; a koṭi of koṭis is a kuli; doubling and doubling the count up to one hundred is also called an asaṃkhyeya. From beginning to end, reaching three asaṃkhyeyas is called three asaṃkhyeyas.
Question: Must attaining Buddhahood definitely take three asaṃkhyeya kalpas?
One view holds: The attainment of Buddhahood is definitely three asaṃkhyeya kalpas. Because gotra and so forth are all equal, and the conditions of the Buddha's great compassion are without bias. The Upāsaka-śīla Sūtra and the Mahāprajñāpāramitopadeśa say: "In the past, under the Buddha Ratnaśikha, I completed the first asaṃkhyeya kalpa; under the Buddha Dīpaṃkara, the second asaṃkhyeya was completed; and reaching the Buddha Vipaśyin, the third asaṃkhyeya was brought to completion. Thereafter, for ninety-one kalpas, I separately cultivated the causes of the marks and signs." Therefore we know that attaining Buddhahood definitely takes three asaṃkhyeya kalpas. For this reason, the treatise says "all pass through […]". As for sūtras saying that kalpas are indefinite, they speak comparatively regarding the Buddhas of various realms, or in accordance with the faculties and practices of sentient beings. For such-and-such a realm and such-and-such Buddhas, it is fixed that only after so much time is Buddhahood attained.
Another view holds: The kalpas of time for attaining Buddhahood are indefinite, because the meaning stated across various sūtras and treatises is indefinite. Here we briefly show five indefinite aspects: first, across all directions, although worlds are of various types, the length or shortness of kalpa numbers is not fixed as one; second, even within a single direction, across earlier and later kalpas, the length of human lifespans is also not fixed; third, bodhisattvas do not abide exclusively in a single world to perform their superior practices; fourth, all time divisions are inexpressible—in a single thought-moment where non-arising occurs, Buddhahood is attained; fifth, kalpas interpenetrate: one is all, and within a single thought-moment multiple kalpas are contained. Stating that Buddhahood is attained only after three asaṃkhyeyas merely follows the majority and is spoken for the slowest, to reveal that cultivating the mass of merit takes a long time and to broadly set a limit; in seeking the true principle, it is not fixed. Because the Mahāyāna Dharma is the supreme vehicle, if there are those who cultivate vigorously without interruption, there is also the possibility of swiftly attaining Buddhahood. Therefore the Sarvatathāgatatattvasaṃgraha and other sūtras all state that in the present life one ascends the Ground of Joy, and after sixteen births attains bodhi. The Great Prajñāpāramitā states that a vigorous bodhisattva, continuing for a hundred kalpas, directly attains Buddhahood. Otherwise, why would the bodhisattva Śākyamuni have already practiced wondrous deeds under the Buddha Mahābhijñājñānābhibhū? And how could it be said that he surpassed Maitreya? If he surpassed small kalpas, the same applies to great kalpas. Therefore, one must not grasp that three asaṃkhyeya kalpas is fixed.