At the centre of the liturgy of the Word […] there is a saying of the Prophet Hosea to which Jesus refers in the Gospel: "I desire steadfast love and not sacrifice, the knowledge of God, rather than burnt offerings" (Hos 6: 6). It is a key word, one of those that bring us into the heart of Sacred Scripture. The context in which Jesus makes it his own is the calling of Matthew, a "publican" by profession, in other words a tax collector for the Roman imperial authority: for this reason the Jews considered him a public sinner. Having called Matthew precisely when he was sitting at his tax counter - this scene is vividly depicted in a very famous painting by Caravaggio -, Jesus took his disciples to Matthew's home and sat at the table together with other publicans. To the scandalized Pharisees he answered: "Those who are well have no need of a physician, but those who are sick.... For I came not to call the righteous, but sinners" (Mt 9: 12-13). Here, the Evangelist Matthew, ever attentive to the link between the Old and New Testaments, puts Hosea's prophecy on Jesus' lips: "Go and learn what this means, "I desire mercy, and not sacrifice'".
These words of the Prophet are so important that the Lord cited them again in another context, with regard to the observance of the Sabbath (cf. Mt 12: 1-8). In this case too he assumed responsibility for the interpretation of the precept, showing himself to be "Lord" of even the legal institutions. Addressing the Pharisees he added: "If you had known what this means, "I desire mercy, and not sacrifice', you would not have condemned the guiltless" (Mt 12: 7). Thus in Hosea's oracle Jesus, the Word made man, fully "found himself", as it were; he wholeheartedly made these words his own and put them into practice with his behaviour, even at the cost of upsetting his People's leaders. God's words have come down to us, through the Gospels, as a synthesis of the entire Christian message: true religion consists in love of God and neighbour. This is what gives value to worship and to the practice of the precepts.
[Pope Benedict, Angelus 8 June 2008]