The rising sun as typus Christi

Iam noctis umbra linquitur,
polum caligo deserit,
typusque Christi, lucifer
diem sopitum suscitat.

     Stanza 2 of the anonymous 5th or 6th century hymn "Deus, qui caeli lumen es."  One hundred Latin hymns:  Ambrose to Aquinas, ed. Walsh & Husch, Dumbarton Oaks medieval library (Cambridge, MA:  Harvard University Press, 2012), 119 (118-121):

The shades of night are left behind,
the murk vanishes from the sky;
the light-bearer, symbol of Christ,
awakens now the slumbrous day.