大佛頂如來放光悉怛多般怛羅大神力都攝一切呪王陀羅尼經大威德最勝金輪三昧呪品 1.205

1.205

「如西方天王印，屈頭指入作拳，大指來去。若作法欲召藥叉神，先喚毘沙門天供養，然後召藥叉。皆重拳為印，相重疊於膝上。」

"Like the mudrā of the Heavenly King of the West, bend the index finger in to form a fist, with the thumb moving back and forth. When performing the ritual, if wishing to summon yakṣa spirits, first summon Vaiśravaṇa Deva to make offerings, and then summon the yakṣas. All form the mudrā by piling fists, resting one upon the other on the knees."