Augustine of Hippo

"For behold, God helpeth me" [Psalm 54:4]. Even themselves know not themselves, amid whom I am hiding. But if they too were to set God before their face, they would find in what manner God helpeth me. For all holy men are helped by God, but within, where no one seeth. For in like manner as the conscience of ungodly men is a great punishment, so a great joy is the very conscience of godly men. …

On the Psalms, Psalm 54 ↗

Hilary of Poitiers

The introduction of a pause marks a change of person. He no longer speaks but is addressed. For now the prophetic utterance assumes a general character. Thus immediately after the prayer addressed to God, he has added, in order that the confidence of the speaker might be understood to have obtained what He was asking even in the very moment of asking: Behold, God is My helper and the Lord is the upholder of My soul. He has requited evil unto Mine enemies. …

Homily on Psalm 54 ↗

Thomas Aquinas

"For behold, God helps me." Here he shows that he has been heard in his prayer. And first he shows that he has been heard with regard to one thing. Second, he sets forth what he has been heard with regard to other things, at "turn back evils." It was said above that the prayer was for himself, when he says "save me," and for his enemies, when he says "in your power." First, therefore, he says that he has been heard on his own behalf, because he says he has been saved. …

Exposition on the Psalms of David ↗