續一切經音義 4.178

4.178

阿閦（下又作閦同初六反梵語不妙古云阿插一也應云惡蒭此云無動即東方佛名也）。

阿閦 (Akṣobhya): The lower [character is] also written as 閦, identical to the fanqie chu + liu. The Sanskrit transcription is imperfect; in antiquity it was said as Acha (阿插), which is the same. It should be said as Akṣubhya (惡蒭); here this means 'Immovable' (Wudong), namely the name of the Buddha of the eastern direction.