俱舍論記 5.20

5.20

「此非善說違我宗故」者，此即第六毘婆沙師理盡言窮作此說也。

As for "This is not well-spoken, because it contradicts our tenets": this is the sixth, [namely,] the Vaibhāṣika making this statement when their reasoning is exhausted and words have run out.