This is the second time in Matthew that Jesus tells the Pharisees to go and learn the meaning of the words, I desire mercy, not sacrifice. He also told them this at the beginning of chapter 9 at the calling of Matthew when he held a dinner for Jesus and tax collectors and “sinners” were at the table with them. The Pharisees complained to his disciples about this behavior (eating with sinners, i.e., those who break or do not follow the Mosaic law), provoking the same response from the Lord.
Here, in Matthew 12, there is a slightly different context concerning a violation of Sabbath law by the disciples’ plucking grain to eat. It also recalls Jesus’ woes to the Pharisees in the Matthew 23 where he says that they have neglected the weightier matters of the law: justice and mercy and faith, calling them “blind guides.”
Jesus is quoting Hosea 6:6 in both these instances: “For I desire steadfast love and not sacrifice, the knowledge of God rather than burnt offerings.” It is a theme that occurs elsewhere in the Old Testament. Isaiah 58 famously rebukes Israel for their false fasting, which is somewhat the same thing. The Psalms speak of it several times. Psalms 40:6 says, Sacrifice and offering you do not desire, but you have given me an open ear. Psalm 51 famously states at its end, For you have no delight in sacrifice; if I were to give a burnt offering, you would not be pleased. The sacrifice acceptable to God is a broken spirit; a broken and contrite heart, O God, you will not despise, something so seemingly scandalous that a redactor later felt it necessary to add a final verse that attempted a sort of correction! Proverbs 21:3 says, To do righteousness and justice is more acceptable to the Lord than sacrifice. Ecclesiastes 5:1 says, Guard your steps when you go to the house of God; to draw near to listen is better than the sacrifice offered by fools.
Mercy is so obviously a characteristic of love that it goes without saying, for you cannot love without having mercy. And without love, as St. Paul so memorably told the Corinthians, nothing else matters or carries any weight. Jesus blessed the merciful in the fifth Beatitude, promising that they shall obtain mercy. Mercy is a necessary ingredient, as it were, of forgiveness and unless we forgive others, we cannot find forgiveness ourselves (Mt 6:15).
How can we show mercy to one another? It is really the only thing we have to keep us from judging one another and finding fault. We cannot hope to love without showing mercy. Mercy does not deny that there is sin and guilt. It does not attempt to pretend that there is no injustice, selfishness and needless suffering caused by our actions and behaviors in the world. What mercy does is to choose to meet those dark realities not with anger and condemnation, but with forgiveness and love. We ought to contemplate that if God had not had infinite mercy on ourselves, where would we be? “If you Oh Lord should mark our guilt, who would survive? But with you is found mercy and redemption.” Psalm 130:3-4