Why should the wicked fear God’s mercy? Because His mercy for us means wrath upon our oppressors.
Psalm 59 has one of the most complicated arrangements. It’s remarkable that a man on the run, as David was, took the time to weave his thoughts into such exquisite designs. The psalm is divided in two, with Part 1 (vv 1-10a) ending with the words, “I will wait for You, O You his Strength; for God is my defense. My God of mercy shall come to meet me” (vv 9-10). Part 2 (vv 10b-17) has a similar conclusion: “To You, O my Strength, I will sing praises; for God is my defense, my God of mercy” (v 17). You see the “threefold cord”? God is my Strength, my Defense, and my Mercy. His strength empowers us, His defense encircles us, and His mercy enables us—to get through the most challenging of circumstances. Thank you, David, for that! But notice that these two major parts are again subdivided, each by a Selah, thus forming four stanzas. Each of the stanzas before the Selahs start with a call for victory, although the first is supplication and the second is affirmation. “Deliver me from my enemies, O my God” (v 1), and “God shall let me see my desire on my enemies” (v 10b). Then the two stanzas after the Selahs begin in a similar way (vv 6, 14-15). We might not find this the sort of conversation for polite society, but extreme circumstances require extreme measures. David is the one being treated as dog food, a not uncommon motif in the Old Testament (1 Ki 14:11; 16:4; 21:19, 23-24; 22:38; 2 Ki 9:10, 36), and David spoke similarly when addressing Goliath (1 Sam 17:46; cf v 43). But he trusts in “Yahweh Elohim of Sabaoth, the Elohe of Israel” (v 5), and such a glorious God is more than enough for one needy man. David would ask for nothing less than God Himself, and God can give us nothing more.