俱舍論記 1.114

1.114

「論曰至如是廣說」者，頌中「彼」字，文有兩釋。此即初釋。此言彼者，彼色等境。謂五識身緣彼五境故言彼識，彼識所依淨色名根。引經意證根是淨色。

Regarding "The Śāstra says: [...] as is explained at length in this way": the word "that" (tad) in the verse has two explanations in the text. This is the first explanation. Here, the word "that" refers to those objects such as visible form. That is, the five consciousness-bodies take those five sense objects as cognitive objects, hence they are spoken of as "that consciousness"; the clear form on which that consciousness depends is called a sense faculty. It cites the intention of the sūtra to prove that the faculties are clear form.