After speaking of the creation (Job 12:7-10), Job seems to have thought of his ancestor Noah, and the great Flood. The Lord permanently "broke down" the antediluvian civilization so that it could not be "built again." Then He "shut him in" (Genesis 8:16) the ark, the one man in that world who had obeyed God.

Source:

KJV Defenders Study Bible, by Dr. Henry Morris, Ph.D.
Publisher: Thomas Nelson
Language: English
DEF 10 ISBN 0-529-10444-x
DEF 10-1 ISBN 0-529-10445-8