Now another disciple presents himself (Lk 9: 57-62): "I will follow you, Lord," he says, "but first Im going to say good-bye to my family." I think this is the meaning: "Let me tell my relatives so they wont go looking for me." And the Lord says: "No one who puts his hand to the plow, and then looks back, is ready for the kingdom of heaven." The East is calling you, and youre looking West (Vocat te Oriens, et tu attendis Occidentem.). (Augustine, Sermon 100, 3; PL 38, 604)

I suppose the last sentence could also be translated: "The sunrise is calling you, and youre looking at the sunset." The Latin of the Benedictus (Lk 1:78) refers to the Oriens ex alto"the dayspring [or dawn] from on high," which Joseph Fitzmyer sees as a messianic reference, derived from the LXX translation of Zech 3:8 and 6:12-13. But Augustine seems never to have referred to the phrase in any of his sermons, where oriens means simply "the East," although in one of them he does a nice riff on Pauls conversions having been his moving from the West of his sins to the East of grace.