續一切經音義 9.207

9.207

疿子（上方未反切韻云熱生細瘡也律文中脚生佛子如芥子顆今詳佛字與疿字書寫人誤不可比丘脚上生佛子甚乖律意也）。

Prickly heat pimples (疿子: the upper character has the fanqie 方未; the Qieyun says fine sores produced by heat; in the Vinaya text, it is written that on the feet grew "fozi" [佛子] like mustard seeds; upon examination, the character 佛 [Buddha] is a scribal error for 疿; it is impossible that "Buddha-sons" grew on a monk's feet, which is entirely contrary to the meaning of the Vinaya).