大般涅槃經義記 1.26

1.26

How is it known that Ānanda was born on the night the Buddha attained the Way? To verify this meaning, one must know the causes and conditions for bestowing the name Ānanda. Ānanda is a foreign word; here it is translated as 'Joy'. Joy has three causes: first, past causes and conditions: when Śākyamuni practiced as a bodhisattva in the past, he saw the Śākyamuni Buddha of the past whose father was named Śuddhodana, mother named Māyā, attendant disciple named Ānanda, and whose realm and retinue were no different from the present; thereupon he made a vow: 'May I in the future attain buddhahood with no difference from now.' Due to this fundamental vow, he has now attained the fruit, and therefore the attendant at present is also named Ānanda. Second, present causes and conditions: Ānanda was handsome and upright, and everyone who saw him was joyful, hence he was named Joy. Third, the parents bestowing the name: by what cause did the parents give him the name Joy? Because he was born at the time of joy. What was the time of joy? The time when the Buddha attained the Way.