俱舍論疏 8.161

8.161

「論曰至故名中有」，此出體釋名也。「有自體起」者，謂異熟五蘊前趣死後、後趣生前，二趣中間，故名中有。兩趣中故，名之為中。四有之中一有攝故，名之為有。中即是有，故名中有。

On the passage from "The treatise says" to "hence it is called intermediate existence": This reveals the real entity and explains the name. "An intrinsic nature of existence arises": this refers to the five skandhas of fruition after death in a prior realm and before birth in a subsequent realm, between the two realms of rebirth; hence it is called intermediate existence (antarābhava). Because it is between two realms, it is called "intermediate." Because it is subsumed under one existence among the four existences, it is called "existence." The intermediate is itself an existence; hence it is called "intermediate existence."