一切經音義 1.178

1.178

踰繕那（上羊朱反繕音善。古云由旬。或云由延。或云瑜闍那。皆梵語訛略也。正云踰繕那。上古聖王軍行一日程也。前後翻譯諸經論中互說不同。文句繁多略而不述。今且案西域記云。踰繕那者自古聖王軍行程也。舊傳一踰繕那有四十里。印度國俗乃三十里。聖教所載唯十六里。如上經論所說。差別不同。考其異端。各有所據。或取聖王或取凡肘或取古尺。取捨雖懷異見。終是王軍一日行程適中取實今依西域記三十里為定。玄奘法師親考遠近撰此行記奉對太宗皇帝所問。其言真實。故以為憑。餘皆不取）。

踰繕那 (The upper character has the fanqie 羊朱 [yú]. 繕 is pronounced 善 [shàn]. Anciently it was called 由旬 [yojana], or 由延, or 瑜闍那; all are corrupt abbreviations of the Sanskrit. The correct form is 踰繕那 [yojana]. It is a single day's march of an ancient sage-king's army. Earlier and later translations in various sūtras and treatises give differing accounts; the texts are numerous and complex, so they are omitted and not detailed here. For now, referring to the Xiyu ji: 'A yojana is the single day's march of an ancient sage-king's army. Old traditions say that one yojana is forty li. The Indian custom makes it thirty li. What is recorded in the sacred teachings is only sixteen li.' As described in the above sūtras and treatises, there are differences. Examining these differing views, each has its basis: some take the sage-king, some take ordinary forearms (cubits), and some take ancient feet. Although opinions diverge on what to adopt, in the end it is a day's march for a royal army. Taking a moderate and realistic estimate, we now follow the Xiyu ji and set it at thirty li. Master Xuanzang personally investigated the distances, wrote this travel record, and presented it in response to Emperor Taizong's inquiry. His words are authentic, so they are taken as authoritative; the rest are not adopted).