大毘盧遮那成佛經疏 13.138

13.138

施無畏菩薩印。作施無畏手，瑜伽中（如釋迦印也）申臂向上，令掌外向，即是也。此印示行五法也，地為信、水為進、火為念、風為定、空為惠。諸佛菩薩以身口說法，今此印是表此五根力也。真言。

The mudrā of the Bodhisattva Abhayaprada. Make the fear-granting (abhaya) hand; in yoga (like the Śākyamuni mudrā), extend the arm upward with the palm facing outward; this is it. This mudrā indicates the practice of the five dharmas: earth is faith, water is diligence, fire is mindfulness, wind is concentration, and space is wisdom. The buddhas and bodhisattvas preach the Dharma through body and speech; now this mudrā represents these five faculties and powers. The mantra: