Ex. 12:26 "And it shall come to pass when your children shall say unto you, 'What mean ye (you, not we) by this service?' 13 That ye shall say, ..."
Compare to Ex. 13:8 "And thou shalt shew thy son in that day, saying, This is doen because of that which the LORD did unto me (not us)when I (not we) came forth out of Egypt.
Compare this to Deut. 6:20-21 (following the 10 commandments, ch. 5, and the Shema), "And when thy son asketh thee in time to come, saying, What mean the testimonies, and the statutes, and the judgements, which the LORD our God hath commanded you? 21 Then thou shalt say to thy son, We were Pharaoh's bondmen in Egypt; and the LORD brought us out of Egypt with a mighty hand."
{I always thought this reference heightened the irony of the exchange between Jesus and the crowd, John 8:33, "We were never in bondage to any man! How sayest thou, Ye shall be made free." Yes, they were under Rome's yoke at the time, but they repeated the above covenantally on a regular basis.}
Here's two questions for a proP-C: what is the origin of the bar-mitzvah and it's signification? Why was Jesus up in Jerusalem for catechesis at age 12?