法華義疏 1.240

1.240

「阿難」者，此云歡喜，一者形容端正見者歡喜；二者佛得道夜生，謂歡喜日生名歡喜；三者過去發願願名歡喜。支道林云「博門，又云無染著，其人初果具足煩惱見天龍女不起染心，故云無染」也。是斛飯王之子也。

"Ānanda" is translated here as "Joy" (Huānxǐ). First, his physical appearance was dignified and upright, so that whoever saw him was filled with joy; second, he was born on the night the Buddha attained the Way, so being born on a day of joy, he was named "Joy"; third, in the past he made a vow wishing for the name "Joy". Zhi Daolin says: "It means 'Broad Door' (Bómén); it is also said to mean 'Free of Defilement' (Wúrǎnzhù), for though having attained the first fruit he still possessed defilements, yet upon seeing heavenly and nāga maidens no defiled thoughts arose in him; hence he is called 'Free of Defilement'." He was the son of King Droṇodana.