Luke 2:21 - 24
NLT - 21 Eight days later, when the baby was circumcised, he was named Jesus, the name given him by the angel even before he was conceived. 22 Then it was time for their purification offering, as required by the law of Moses after the birth of a child; so his parents took him to Jerusalem to present him to the Lord.
I have never heard it suggested that the Ten Commandments (TC) were all that comprised the Law. Being Jewish, yet growing up in Christian schools, I have always been taught that the Law was much more than the TC, although it included the TC. The listing of the TC are found in Ex 20 and repeated in Deut 5. We Jews essentially define the Law (Torah) as Genesis through Deuteronomy (even though much of that is narrative and not laws). By way of example, when questioned about the greatest commandment of the Law, Yeshua (Jesus) actually replied that there were TWO great commandments: Love God and love your neighbor as yourself (Matt 22:36-40). Yet, if you look up these two great commandments, neither one of them is found in the TC. To be sure, the first one is from Deut 6:5, and the second one is from Lev 19:18. Actually if you summarize the contents of the Ex 20 list, you could say the first four govern our relationship to God, and the final six govern our relationship to our fellow man. This would make these "two great commandments" a sort of distilled summary of the TC themselves. Conclusion: The TC is perhaps the comprehensive summary of the Law, written by the very finger of God, but it is clearly not the whole of the Law. The rest of the commandments of God were, of course, dictated to and written down by Moses.