妙法蓮華經玄贊 10.266

10.266

釋名者，「音」謂音聲，「妙」謂殊妙。昔住因中好設樂以供佛，今居果位善說法以利生，雙彰業、德以標其名，故稱妙音菩薩。此品明彼事，故名妙音菩薩品。

Regarding explaining the title: 'Voice' (svara) refers to vocal sound; 'Wonderful' (gadgada/mañju) refers to distinct excellence. Formerly, when abiding in the causal stage, he took joy in offering music to buddhas; now, residing in the fruitional stage, he skillfully expounds the Dharma to benefit sentient beings. Manifesting both his past action and his present virtue to mark his name, he is therefore called Gadgadasvara ('Wonderful Voice') Bodhisattva. Since this chapter clarifies his deeds, it is called the Gadgadasvara Bodhisattva Chapter.