Gregory the Dialogist

That He That hath begun would bruise me! For very often the Lord begins to work in us the bruising of our vicious habits, but when the mind is lifted up at the very first step of its progress, and when it already exalts itself as on the ground of its virtuous attainments, it opens an entrance to the adversary, that rages against it, who penetrating into the depths of the heart, dashes in pieces all that he may find therein springing from the earnestness of a good beginning, and shews himself the more violent in the breaking of it in …

Morals on the Book of Job, Book VII ↗

Thomas Aquinas

He expresses the content of the prayer saying, "May he who began this," i.e. to afflict me, "destroy me," in death. He continues, "May he free his hand and cut me down." The hand of God expresses the divine power by which God has afflicted him, and God binds his hand in a way from his mercy and by his will when he does not afflict him. However, God frees his hand in a sense when the divine chastisement that strikes him is directed to killing him.

Commentary on Job ↗