O Oriens, splendor lucis aeternae, et sol justitiae: veni, et illumina sedentes in tenebris, et umbra mortis.

O Morning Star, splendour of light eternal and sun of righteousness: Come and enlighten those who dwell in darkness and the shadow of death.

Isaias 9:2

The people that walked in darkness, have seen a great light; to them that dwelt in the region of the shadow of death, light is risen.

Malachias 4:1-3

For behold the day shall come kindled as a furnace: and all the proud, and all that do wickedly shall be stubble: and the day that cometh shall set them on fire, saith the Lord of hosts, it shall not leave them root, nor branch. But unto you that fear my name, the Sun of justice shall arise,  and health in his wings: and you shall go forth and shall leap like calves of the herd. And you shall tread down the wicked when they shall be ashes under the sole of your feet in the day that I do this, saith the Lord of hosts.

Check out my publication which provides commentary on the O Antiphons, in addition to direction on how to pray the Mass during Advent. This publication is a perennial addition to your library. Go HERE for more information on Praying the Mass During Advent and all publications by Filii Passionis.