Psalm 107    

“bars.” The “bars” were strong wooden beams that were placed behind the doors so they could not be opened and could withstand pounding from the outside without giving way. Those bars were the origin of the shout “Bar the doors!” when an enemy would approach. No city would have a bar of iron; that would be a hyperbolic way of saying that God was unstoppable.

“the gates of death.” There is no escape from death except by being raised from the dead by God, and because of that, death is compared to a prison that has “gates” and from which no one can escape without God’s help. These “gates” are referred to as the “gates of Sheol” (Job 17:16; Isa. 38:10) and “the gates of death” (Job 38:17; Ps. 9:13; 107:18). Jesus Christ referred to the gates in Matthew 16:18 where in many versions they are translated as “the gates of Hell.”

[For more on the gates of death, see commentary on Matt. 16:18. For more on Sheol, see commentary on Rev. 20:13. For more on dead people being dead, lifeless in every way, see Appendix 4, “The Dead are Dead.”]

“because of the wickedness of those who dwell in it​.” One of the great lessons of the Bible is that the behavior of people affects the land that they live on. This lesson is throughout the Old Testament (cp. Deut. 11:13-17; 28:1, 12, 15, 22-25, 38-40; Lev. 18:24-25; Ps. 107:33-34; Jer. 3:2-3; 12:4; 23:10; Amos 4:6-10). (See commentary on Lev. 18:25).