續一切經音義 6.91

6.91

優曇鉢羅（次徒含反梵語也舊云優曇正云烏曇鉢羅此云祥瑞雲奇異天花也世間無此花若如來下生金輪出現以大福德力故感得此花出現也）。

Udumbara (優曇鉢羅: the second character has the fanqie *tú* + *hán* [tán]. This is Sanskrit. Formerly it was called *yōután*; correctly it is *wūdánbōluó*. Here it is translated as "auspicious cloud," a wondrous celestial flower. This flower does not exist in the human realm. Only when a Tathāgata descends to be born or a golden wheel-turning king appears does this flower manifest through the power of great merit).