It Is Impossible that Glory Should Be Without Radiance

As the light from the lamp is the nature of that which sheds the brightness, and is united with it (for as soon as the lamp appears the light that comes from it shines out simultaneously), so in this place the Apostle would have us consider both the Son is of the Father, and that the Father is never without the Son; for it is impossible that glory should be without radiance, as it is impossible that the lamp should be without brightness.

Gregory of Nyssa commenting on Hebrews 1:3

– Reeves, Michael; Delighting in the Trinity: An Introduction to the Christian Faith; ¬†IVP Academic; Downer’s Grove, IL, Page¬†27