« Ô Light »: the first words in Latin of an antiphon addressed to Saint Dominic, he who in the night of sinners, is like a light that illuminates the good path for getting to true life, Jesus. In struggling against the errors in doctrine and against the lack of generosity in practice, it obtains for the believer the spirit of love of the One who said in his Gospel: « I am the light of the world (Jn 8, 12) ». The antiphon « O Lumen » can be translated as follows: « O light of the Church, teacher of truth, rose of patience, ivory of chastity. You freely poured forth the waters of wisdom. Preacher of grace, unite us with the blessed ».