一切經音義 8.101

8.101

優曇花（梵語古譯訛略也梵語正云烏曇跋羅此云祥瑞雲異天花也世間無此花若如來下生金輪王出現世間以大福德力故感得此花出現）。

Udumbara flower [優曇花] (In the Sanskrit language. The ancient transcription was corrupt and abbreviated. In the Sanskrit language it is properly called udumbara [烏曇跋羅]; here translated as "auspicious cloud," a wondrous celestial flower. This flower does not exist in the mundane world; only when a Tathāgata descends to be born, or a golden wheel-turning king appears in the world, does this flower appear due to the power of their great merit).