Charles Ellicott Commentary Matthew 22:40

"On these two commandments the whole law hangeth, and the prophets." — Matthew 22:40 (ASV)

All the law and the prophets—The words are coupled, as in Matthew 5:17 and Matthew 7:12, to indicate the whole of the revelation of the divine will in the Old Testament. The two great commandments lay at the root of all. The rest merely expanded and applied them; or, as in the ceremonial law, set them forth symbolically; or, as in the laws concerning slavery and divorce, confined their application within limits that the hardness of people’s hearts made necessary. For the glowing assent of the scribe to our Lord’s teaching, and our Lord’s approval of him, see the notes on Mark 12:32-34.