俱舍論疏 29.196

29.196

論「若爾至有如是色等」，犢子部即引前經別文證有我也。既言我有色等，故知有我。

The treatise says: "If that is so... having such visible forms and so forth." The Vātsīputrīyas then cite another passage from a previous sūtra to prove that a self exists: since it says 'I had such visible forms and so forth', we know that a self exists.