Because the Jews took the Torah (“instruction”) seriously, the ground was well-prepared for Jesus’ Sermon on the Mount. Here is one example:
Sirach (Ben Sira) 28:2-4
2 Forgive your neighbor the wrong done to you;
then when you pray, your own sins will be forgiven.
3 Does anyone nourish anger against another
and expect healing from the Lord?
4 Can one refuse mercy to a sinner like oneself,
yet seek pardon for one’s own sins?
Ben Sira, written almost 200 years before Jesus’ birth, gets the principle exactly right. He anticipates the line from the Lord’s Prayer, and Jesus’ additional comment in Matthew 6:14, and even his parable about the unforgiving servant in Matthew 18. Ethically sensitive Jews who studied the Law, the Prophets, and the Writings, were working “good soil” for Jesus’ announcement of the coming of the Kingdom. Jesus does not abandon the “instruction” but fulfills it. A key part of that is “repositioning” mercy as an element of His Father’s approach–without His Father’s mercy (most evident in Jesus, gift-of-God’s-own-Son) we have no chance of fulfilling the Law.