Actually the phrase is
bis orat qui bene cantat… “he who sings well prays twice.”
What St. Augustine did say:
*Qui enim cantat laudem, non solum laudat, sed etiam hilariter laudat; qui cantat laudem, non solum cantat, sed et amat eum quem cantat. In laude confitentis est praedicatio, in cantico amantis affectio…*For he who sings praise, does not only praise, but also praises joyously; he who sings praise, is not only singing, but also loving Him whom he is singing about/to/for. There is a praise-filled public proclamation (praedicatio) in the praise of someone who is confessing/acknowledging (God), in the song of the lover (there is) there is deep love.
wdtprs.com/blog/2006/06/who-sings-well-prays-twice-not/