Luke 2:21 (ESV)
And at the end of eight days, when he was circumcised, he was called Jesus, the name given by the angel before he was conceived in the womb.
There is so much in this one little verse. You have the promise of the new creation signified by the fact that he was circumcised on the eighth day. The eighth day is a mystical sort of reference through out the old testament. Everything is made new again on the eighth day. God created the world in six days, rested on the seventh, renews on the eighth. In this way Jesus resurrection happens on the first day of the week, planned that way. Not merely so he could rest on our Sabbath, but that his resurrection would be on the day after the seventh, a new creation, an eighth day. Boys were circumcised, made new on the eighth day. Women were made pure after 8 days. Just do a word search on it once in scripture, the eighth day. It is not just an arbitrary number.
The full manhood of Jesus is indicated in that he was circumcised. He had flesh and bone and blood like other men. He was fully man. Redeems us as fully man, redeems us with blood.
And this blood he first sheds here. He puts himself under the law for our sake. Here he makes a down payment on our sin. He bleeds not for himself but for us. Here he first suffers under the law for our sake, being cut by a knife in accordance with the law.
And then he is named Jesus. God saves. It is a divine name given by the angel pointing to his full divinity. Our God has become man, suffered under the law, was circumcised and shed blood for us in accordance with the law, that his death might make full payment for our sins.