續一切經音義 9.206

9.206

革屣（上古核反改也字書云獸皮去毛也又更也說文云三十年一世可更革也故從三十口口即國也下所綺反切韻云履不躡跟也舊音義云言革屣者西域皮底鞋也）。

Leather shoes (革屣: the upper character has the fanqie 古核, meaning to change; the character dictionaries say animal hide with the hair removed; it also means renewal; the Shuowen jiezi says thirty years make one generation, which may be renewed [ge], hence it is derived from thirty and 口, 口 being "state"; the lower character has the fanqie 所綺; the Qieyun says shoes without heels; the older pronunciation and meaning glossaries say that leather shoes [gexi] are Western Regions shoes with leather soles).