I got this from John M. Frame, Christ was not only perfectly obedient to God's Law, He was also the substance of the Law...
"Here I wish to say that Jesus is not only a perfect law-keeper (according to his humanity), but that according to his deity he is the one we honor and worship when we keep the law:
4. In the fourth commandment, Jesus is our Sabbath rest. In his presence, we cease our daily duties and hear his voice (Luke 10:38-42).
5. In the fifth commandment, we honor Jesus who has brought us as his “sons” (Heb. 2:10) to glory.
7. In the seventh commandment, we honor him as our bridegroom who gave himself to cleanse us, to make us his pure, spotless bride (Eph. 5:22-33). We love him as no other.
8. In the eighth commandment, we honor Jesus as our inheritance (Eph. 1:11) and as the one who provides all the needs for his people in this world and beyond.