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 1.91

1.91

Furthermore, there is a rite: if someone is made ill by written talismans, incantations, sorcery, or ku-poison, empower seven mustard seeds with the mantra and strike the sick person; upon being struck, the place of sorcery will naturally become known. Also empower once and pour it over the crown of the head; the illness will be eliminated and cured.