阿彌陀經疏 1.193

1.193

經曰：「於意云何，彼佛何故名阿彌陀」，次釋第一問也，彼佛從何義趣名阿彌陀。自下答中為含二義名阿彌陀：一、無量光明故名阿彌陀；二、壽命無量故名阿彌陀。

The sūtra says: "What do you think, for what reason is that Buddha named Amitābha?" Next, this explains the first part, the question: From what meaning is that Buddha named Amitābha? In the answers below, he is named Amitābha because it contains two meanings: first, he is named Amitābha because of immeasurable light; second, he is named Amitābha because of immeasurable lifespan.