"Teacher, which is the greatest commandment in the Law?"

Rabbi Simlai said, "Six hundred and thirteen commandments were given to Moses, 365 negative commandments, answering to the number of the days ofthe year, 248 positive commandments, answering to the number of a man's members.

Then David came and reduced them to eleven [Psalm 15].
LORD, who may dwell in your sanctuary? Who may live on your holy hill? He whose walk is blameless and who does what is righteous, who speaks the truth from his heart and has no slander on his tongue, who does his neighbor no wrong and casts no slur on his fellowman, who despises a vile man but honors those who fear the LORD, who keeps his oath even when it hurts, who lends his money without usury and does not accept a bribe against the innocent. He who does these things will never be shaken.

Then came Isaiah, and reduced them to six [Isaiah 33:15-16].
He who walks righteously and speaks what is right, who rejects gain from extortion and keeps his hand from accepting bribes, who stops his ears against plots of murder and shuts his eyes against contemplating evil- this is the man who will dwell on the heights, whose refuge will be the mountain fortress. His bread will be supplied, and water will not fail him.

Then came Micah, and reduced them to three [Micah 6:8].
He has showed you, O man, what is good. And what does the LORD require of you? To act justly and to love mercy and to walk humbly with your God.

Then Isaiah came again, and reduced them to two, [Isaiah 56:1]
This is what the LORD says: "Maintain justice and do what is right, for my salvation is close at hand and my righteousness will soon be revealed.”

Then came Amos, and reduced them to one, [Amos 5:4]
This is what the LORD says to the house of Israel: "Seek me and live;

Or one may say, then came Habakkuk , and reduced them to one, [Habakkuk 2:4]
"See, he is puffed up; his desires are not upright—but the righteous will live by his faith' [Talmud, Makkot 23b-24a]

Jesus replied: " 'Love the Lord your God with all your heart and with all your soul and with all your mind.' This is the first and greatest commandment. And the second is like it: 'Love your neighbor as yourself.' All the Law and the Prophets hang on these two commandments."
[New testament, Matthew 22:34-40]