法界次第初門 1.127

1.127

九、作者。於名、色、陰、入、界等法中，妄計我有身力手足，能有所作，故名作者。

Ninth is the agent (kāraka). Regarding dharmas such as nāmarūpa, the skandhas, āyatanas, and dhātus, one falsely imputes that the self has physical strength, hands, and feet, and is able to perform actions; therefore it is named agent.