Water and blood

I was reading a little the other day and the thought about when Christ's side was pierced while He was on the cross. We know that water and blood flowed out of the wound. I understand that that was a physical sign of a heart attack, but does it have a spiritual meaning to it as well? We know that during the sacrifices that take place in the Temple and Tabernacle that the water played the role of cleansing and the blood was for covering (Day of Atonement). Does this thought carry through to what Christ did on the cross? In Levi's book on the Tabernacle, every piece of furniture had pictured in some way Christ, it represented something. Well the blood of Christ covers our sins and makes us righteous to God, does the water represent a cleansing. Now I do not want to give you the idea that the water is necessary for our salvation, but what was it's significance. I John 5 deals with the water, and water has a role throughout scripture. Please share your thoughts with me!

On a side note, one of my youth asked me a question the other day about Jesus. When Christ was born, Herod had all the children killed, was Jesus the only child, youth, man, His age in that area?