Matthew 22:35-40:

35One of them, an expert in the law, tested him [Jesus] with this question:

36“Teacher, which is the greatest commandment in the Law?” 37Jesus replied: ” ‘Love the Lord your God with all your heart and with all your soul and with all your mind.’38This is the first and greatest commandment. 39And the second is like it: ‘Love your neighbor as yourself.’ 40All the Law and the Prophets hang on these two commandments.”