What does Psalm 55:10 mean?

Clues in this psalm suggest the rebellion of David's son, Absalom, is the specific event in view (2 Samuel 15:14; Psalm 55:3–8). David's former advisor, Ahithophel, aided the conspiracy (2 Samuel 15:31; Psalm 55:12–13). The prior verse noted the conflict plaguing "the city," which likely means Jerusalem (Psalm 55:9). This verse continues to mourn the presence of evil within David's home. Walls were a city's primary defense. Guards and watchmen would patrol these, allowing them to see threats approaching the city and monitor for disturbances inside. When wicked people "walk the walls," one would expect evil and danger to thrive.

Sin and negative consequences always travel together. The first human couple sinned and trouble followed. The earth was placed under a curse. Death came to humanity. Fellowship with God was broken (Genesis 3:24). When wickedness increased in the days of Noah, God destroyed the earth with a flood (Genesis 6:5–7). When the people of Israel and Judah broke their covenant with God and plunged into idolatry, God sent the Assyrians and Babylonians against them (Isaiah 8:7–8).

The godless depravity David saw in Jerusalem foreshadows the intense wickedness that will exist in Jerusalem in the tribulation. Then, the false prophet will force people to worship the image of the beast that he sets up in the temple. This blasphemous act will cause non-compliant people to forfeit their lives (Revelation 13:11–¬18). Jesus foretold that in the tribulation lawlessness will abound (Matthew 24:12).