大毘盧遮那成佛經疏 13.53

13.53

次作如來鉤印。先以左手空指，壓餘四指之頭令如環狀，次以右手三指內於環中，右手大指加左大指之外，而屈入掌中捻右手三指亦令如環狀，舒右手風指而稍屈第三節令如鉤形，即是也。作此鉤印，能召十方一切諸佛菩薩，皆令集會道場，亦能滿足十地之位，況餘八部之類未生善心者而不來至耶？

Next is the Tathāgata's Hook (Aṅkuśa) Seal. First, with the space finger of the left hand, press the tips of the remaining four fingers to form a ring shape; next, insert the three fingers of the right hand into the ring; place the right thumb over the outside of the left thumb, bending it into the palm to press the three fingers of the right hand, also making them like a ring shape; extend the right wind finger and slightly bend the third joint into the shape of a hook; that is it. Making this hook seal can summon all buddhas and bodhisattvas of the ten directions, causing them all to assemble at the bodhimaṇḍa, and can also fulfill the stations of the ten bhūmis; how much more so for the classes of the remaining eight kinds of beings who have not yet generated a wholesome mind—how could they not arrive?