俱舍論記 3.78

3.78

「毘婆沙師至煩惱魔故」者，第二解佛留、捨。蘊魔意欲留連行者，多時住世相續不斷；死魔意故催促行者，令不住世速歸無常。如來捨壽顯伏蘊魔，復留三月顯伏死魔。世尊先於菩提樹下，已伏天魔、煩惱魔故，留、捨正顯伏蘊、死魔，義便兼顯伏天、煩惱，總明如來伏四魔也。又解：若不延、促，唯破二魔。顯佛世尊具破四魔，故令延、促。

"The masters of the Vibhāṣā [...] because he had subdued the Māra of afflictions": the second explanation of the Buddha's retaining and discarding. The intent of the Skandha-māra is to prolong the practitioner's stay, abiding long in the world without interruption; the intent of the Mṛtyu-māra is intentionally to hasten the practitioner, so that he does not abide in the world but quickly returns to impermanence. The Tathāgata's discarding of lifespan shows the subduing of the Skandha-māra, and further retaining three months shows the subduing of the Mṛtyu-māra. Because the World-Honoured One had already subdued the Deva-māra and the Kleśa-māra beneath the Bodhi tree previously, the retaining and discarding primarily show the subduing of the Skandha-māra and Mṛtyu-māra, and incidentally also show the subduing of the Deva-māra and Kleśa-māra, collectively demonstrating that the Tathāgata subdued the four Māras. Another explanation states: If he had not prolonged and curtailed, he would only have crushed two Māras; to show that the Buddha, the World-Honoured One, completely crushed all four Māras, he therefore prolonged and curtailed [his life].