PL 51, col. 91

Carmen de ingratis (Prosper Aquitanus), J. P. Migne

105 Unde voluntatis sanctae subsistat origo,
Unde animis pietas insit, et unde fides:
Adversum ingratos falsa et virtute superbos,
Centenis decies versibus excolui.

Text from the Corpus Corporum (University of Zurich).

Cited in the encyclopedia

Prosper of Aquitaine