What’s the best way to punish evildoers? Make the evildoers experience the wickedness that they had planned to inflict on others, in other words, give them a taste of their own medicine. The book of Psalms has a lot of passages where the psalmist asked God for this very thing to happen. Here are the passages I found.

Make them bear their guilt, O God, let them fall by their own counsels. 5:10

He makes a pit, digging it out, and falls into the hole which he has made. 7:15

His mischief returns upon his own head, and on his own pate his violence descends. 7:16

The nations have sunk in the pit which they made; in the net which they hid has their own foot been caught. 9:15

The wicked are snared in the work of their own hands. 9:16

Let the net which they hid ensnare them; let them fall therein to ruin! 35:8

Their sword shall enter their own heart. 37:15

They dug a pit in my way, but they have fallen into it themselves. 57:6

He loved to curse; let curses come on him! 109:17

He clothed himself with cursing as his coat, may it soak into his body like water, like oil in his bones! 109:18

May my accusers be clothed with dishonor; may they be wrapped in their own shame as in a mantle! 109:29

Those who surround me lift up their head, let the mischief of their lips overwhelm them! 140:9

Let the wicked together fall into their own nets, while I escape. 141:10

So let the wicked plot and plan all they want against us. We have nothing to fear because God will bring their own evil crashing down on their heads.