Jerome

And Adam was cast out, and he made him dwell opposite the paradise of pleasure. And he established Cherubim and a flaming sword, which turned to guard the way to the tree of life. There is much more meaning in the Hebrew than is understood here. For it says: And Adam was cast out, no doubt by the Lord: And he made him dwell before the paradise of pleasure, Cherubim, and a flaming sword, which turned, and guarded the way to the tree of life. …

Hebrew Questions on Genesis ↗

Bede

And he drove Adam out and placed before the paradise of delight the cherubim and the flaming sword, which turned every way to guard the way to the tree of life. The ancient translation has it thus: "And he drove Adam out and placed him opposite the paradise of delight, and appointed the cherubim and the flaming sword, etc." If we follow this, we must believe that this was done for the sake of signification, but still done, so that the sinner, indeed, would dwell in misery against the paradise, where blessed life was also spiritually …

Commentary on Genesis (Hexaemeron) ↗

Bonaventure

That remedy ought to have had efficacy first upon those who believed in Christ, and by believing hoped, and by hoping loved; and on this account He ought to have descended to the nether regions immediately for their liberation. Whence, when the gate of heaven was opened through the passion of Christ—who by making satisfaction removed the flaming sword, by changing the divine sentence—He snatched from hell all His members.

Breviloquium ↗