佛祖統紀 30.26

30.26

減至一百歲時。第四釋迦牟尼佛出世。本在一萬歲時。為觀眾生無機可度。至百歲劫末苦逼。故出乎世（長阿含經大智度論）。

When it decreased to one hundred years, the fourth Buddha, Śākyamuni, appeared in the world. Originally [destined for] when [lifespan was] 10,000 years, observing that sentient beings lacked the capacity to be delivered, he appeared in the world at the end of the kalpa when [lifespan was] one hundred years and suffering was oppressive (Dīrghāgama, Mahāprajñāpāramitāśāstra).