一切經音義 91.198

91.198

佛蹠（下征亦反廣雅蹠履也楚辭踐也淮南子云鳥排空而飛獸蹠實而走是也形聲字也）。

佛蹠 ("The Buddha's footprints": the second character has the fanqie 征 + 亦 [zhēngyì]. The Guangya says: "Zhí means to tread." The Chuci says: "To tread on." The Huainanzi states: "Birds beat the empty sky to fly, while beasts tread upon solid ground to run," which is this meaning. It is a phono-semantic character).