Why would Jesus need to be Sanctified?

In John 17, Jesus says "I sanctify Myself for them, so they also may be sanctified by the truth." Hunh? Isn't Jesus already perfectly holy (or sanctified)? Why would he need to sanctify Himself?

Compare with Hebrews 13:12, where it says "Therefore Jesus also suffered outside the gate, so that He might sanctify the people by His own blood."

Both these verses follow the pattern: Jesus does/did X so that people could be sanctified by Y. Is it fair to say that sanctifying Himself is parallel to suffering outside the gate, i.e., dying on the cross. If so, then how is truth parallel to the blood?

I think this means that Jesus set himself apart to die--He dedicated himself to die. This was what He meant in John. This is similar to the way God told the Israelites to dedicate everyone in conquered cities to Him, and it meant to kill them. I think this sanctification is talking about the sanctification of salvation, and I think that it is faith in the truth about the blood of Jesus which allows salvation--by grace THROUGH FAITH.