一切經音義 21.166

21.166

夷坦（夷以脂反坦他嬾反毛詩傳曰夷易也謂簡易之道言省力易行者也廣雅曰坦平也）。

Level and even (The fanqie for 夷 is 以脂 [yí]; the fanqie for 坦 is 他嬾 [tǎn]. The Mao Shijing commentary says: '夷 means easy, referring to the path of simplicity and ease, meaning that which saves effort and is easy to follow.' The Guangya says: '坦 means flat or level').