Lifnim Mishurat Hadin
Those who see Judaism as a religion of precise law may be surprised to hear that the Jewish ideal is always to act beyond the letter of the law: lifnim mishurat hadin in Hebrew, literally meaning, inside the line of law.
In a bold statement of this idea, the 13th-century commentator Nachmanides writing about Deuteronomy 6:18, You shall do what is right and good in the eyes of God teaches that the laws of the Torah cannot legislate for more than a fraction of the ethical dilemmas we will face in life. However, through keeping the Torah we can fine-tune our moral sensibilities so that we will be able to intuit whats the right thing to do in cases that are not legislated and to do more than the Torah requires in situations that are. The Talmud even considers the paradoxical possibility that going beyond the letter of halachah is itself what the halachah requires of us (Baba Metzia 83a).
In the period leading up to Rosh Hashanah, we fear what might be the consequences if God were to judge us with precise justice, untempered by compassion. In numerous places, the Rabbis teach that if we behave towards others lifnim mishurat hadin, with generosity and kindness beyond what is strictly required, then we might hope that God will act lifnim mishurat hadin with us, and forgo the harshness that rigorous application of justice would require.