俱舍論記 22.118

22.118

「即於彼物至名世俗諦」者，釋世俗諦。即於彼物瓶未破時、水未析時，以世想名施設瓶、水。假施設有故，名為世俗。依世俗理說瓶等是實，名世俗諦。

Regarding "Precisely with respect to that thing ... is called conventional truth": This explains conventional truth. Precisely with respect to that thing, when the jar is not yet broken and the water is not yet analyzed, one designates jar and water by worldly conceptions and names. Because they exist as nominal designations, they are called conventional. Based on conventional reasoning, one says that jars and the like are real, which is called conventional truth.