Augustine of Hippo

He adds, how He became our refuge, since He began to be that, viz. a refuge, to us which He had not been before, not that He had not existed before He became our refuge: "Before the mountains were brought forth, or ever the earth and the world were made: and from age even unto age You are" [Psalm 90:2]. Thou therefore who art for ever, and before we were, and before the world was, hast become our refuge ever since we turned to You. …

Exposition on Psalm 90 ↗

Jerome

Before the mountains were made, and the earth and the world were formed. At this place a heresy creeps in: If he was made a refuge for us before the mountains were made and the earth and the world were formed, then souls existed before the world came to be. For what does Scripture say? Lord, you have been made a refuge for us: from generation, it says, to generation: from the beginning of the world, before the beginning of the world. This is what they say. And do not think, he says, that I am the one saying it. …

Homily 19, on Psalm 89 ↗