佛祖統紀 30.4

30.4

梵語劫波。此云分別時節（智論）以人壽八萬四千歲。百年命減一年。減至十歲。百年增一年（或云子倍父壽）復增至八萬四千歲。如是一減一增為一小劫。二十增減為一中劫。總成住壞空四中為一大劫（新婆沙論）今論過去現在未來三世各一大劫。

The Sanskrit word kalpa is translated here as 'differentiating periods of time' (Mahāprajñāpāramitopadeśa). Taking human lifespan at eighty-four thousand years, every hundred years the lifespan decreases by one year, decreasing until it reaches ten years; every hundred years it increases by one year (or it is said that the child doubles the lifespan of the father), increasing again up to eighty-four thousand years. Such one decrease and one increase constitutes one small kalpa. Twenty decreases and increases constitute one medium kalpa. Combining the four medium [kalpas] of formation, abiding, destruction, and void constitutes one great kalpa (New Mahāvibhāṣā). Here we discuss one great kalpa for each of the three times: past, present, and future.