Gregory the Dialogist

Lo, the giants groan under the waters. For it was fitting that by rebuking he should first beat down the swelling of earthly wisdom, and by instruction afterwards pass on to words replete with mysteries. Thus by 'giants,' either apostate Angels, or all proud men may without objection be understood. For hence it is said by the Prophet, The dead shall not live, the giants shall not rise up again. For whom does he call 'the dead' saving sinners, and whom does he designate 'giants' save those, who over and above take pride in sin. …

Morals on the Book of Job, Book XVII ↗

Thomas Aquinas

Then, lest Job seem to detract from the power of God in anything, he commends it as much more all encompassing than did Baldath, enumerating the many effects of divine power. He begins from those effects which God powerfully worked in the human race in the time of the flood. …

Commentary on Job ↗