By mercy and truth iniquity is purged; atoned for. The combination "mercy and truth" occurs in Proverbs 3:3 (where see note), and intimates love to God and man, and faithfulness in keeping promises and truth and justice in all dealings.
It is by the exercise of those graces, not by mere external rites, that God is propitiated (see on Proverbs 10:2). A kind of expiatory value is assigned to these virtues, which, indeed, must not be pressed too closely, but should be examined by the light of such passages in the New Testament as Luke 11:41; Acts 10:4.
Of course, such graces show themselves only in one who is really devout and God fearing; they are the fruits of a heart at peace with God and man, and react on the character and conduct. The LXX; which places this distich after Proverbs 15:27, translates, "By alms and faithfulness ( πίστεσιν) sins are cleansed," confining the term "mercy" to one special form, as in one reading of Matthew 6:1, "Take heed that ye do not your righteousness [al.
alms] before men." By the fear of the Lord men depart from evil. The practice of true religion, of course, involves abstinence from sin; and this seems so unnecessary a truth to be formally stated that some take the "evil" named to be physical, not moral evil; calamity, not transgression.
But the two clauses are coordinate, and present two aspects of the same truth. The first intimates how sin is to be expiated, the second how it is to be avoided. The morally good man meets with pardon and acceptance, and he who fears God is delivered from evil.
So we pray, in the Lord's Prayer, "Forgive us our trespasses, and deliver us from evil." Septuagint, "By the fear of the Lord every one declineth from evil" (comp. Proverbs 14:27).