The image of sin as pregnancy is frequently found in Scripture (Job 15:35; Isa. 33:11; 59:4, 13; James 1:13–15). Sinners “conceive” sin that, like a monstrous child, eventually grows up and destroys them. They dig pits and fall into them themselves (see 9:16; 37:14–15; 57:6; 1 Sam. 25:39; Prov. 26:27; Eccl. 10:8; Ezek. 19:4). The trouble they cause comes back on their own heads (Gal. 6:7). There is a work of divine retribution in this world, and nobody can escape it. “Though the mills of God grind slowly, yet they grind exceeding small” (Friedrich von Logau).
God abandoned King Saul to his own ways (1 Sam. 15), and ultimately both the arrow and the sword caught up with him (vv. 12–13; 1 Sam. 31:3–4). He wanted to kill David, but his own sword killed him. Pharaoh ordered the male Jewish babies to be drowned in the Nile, and his own army was drowned in the Red Sea. Haman built a gallows on which to hang Mordecai, and Haman himself was hanged on it (Est. 7).
The psalm closes with David extolling the Lord, not for the fact that sinners have been judged, but because the righteousness of God has been magnified. The fact that people are ensnared by their own sins and ultimately judged brings no joy to the hearts of believers, but the fact that God is glorified and His righteousness exalted does cause us to praise Him. God judges sin because He is holy, and His decrees are just (v. 6). “Even so, Father, for so it seemed good in your sight” (Luke 10:21). Finally, keep in mind that God gave His own Son to die for the sins of the world, so that He might uphold His own holy law and at the same time offer His mercy and grace to all who will believe. People may not like the way God runs His universe, but, as Dorothy Sayers expressed it, “for whatever reason God chose to make man as he is—limited and suffering and subject to sorrows and death—He had the honesty and the courage to take His own medicine” (Christian Letters to a PostChristian World [Eerdmans, 1969], 14).