俱舍論疏 14.156

14.156

論「不爾應言受一分等」，反難釋也。既言學一分，不言受一分，故知就能持說。

On the Śāstra's phrase: "Otherwise, it should say 'receiving one part, etc.':" This explains by turning the objection back upon the opponent. Since it says "training in one part" and does not say "receiving one part," one therefore knows that it speaks in terms of ability to observe.