俱舍論疏 27.18

27.18

「論曰至無邊心力」，釋佛身力量也。那羅延，是神名，此云人種。有三說不同。一云：佛力等那羅延力。二云：一一支節等那羅延力。三云：身力無邊，若不爾者即應不能持無量心力。

"The Śāstra says [...] immeasurable mental power": this explains the strength of the Buddha's body. Nārāyaṇa is the name of a deity, translated here as "human lineage". There are three different explanations: The first says: the Buddha's strength is equal to the strength of Nārāyaṇa. The second says: each and every bodily joint is equal to the strength of Nārāyaṇa. The third says: the physical strength is boundless, for if it were not so, it would be unable to support immeasurable mental power.