'Enemy' in the Bible

Lately my people have acted like an enemy you strip travelers who thought they were as secure as those who return from war.

Don't be glad on my account, my enemy. When I fall, I'll get up. Though I sit in darkness, the LORD is a light for me.

Then my enemy will observe it, and shame will engulf the ones who asked me, "Where is the LORD your God?' My own eyes will see them, they will be trampled on like mud in the streets.