Why do people kiss the priest's hand and ask his blessing?

It's easy for people to see the priest but forget that what is so significant and special about him is the priesthood he carries within him, which is Christ's priesthood. The priest himself is less significant. Christ is what is significant. There's an old joke about when a priest gets ordained and people come up asking for his blessing. They relate it to the donkey going into Jerusalem.

The donkey says, "Oh my goodness, all these people are here to see me," and they're all throwing down palm branches, and he thinks, "I'm the most special donkey in the world." No. The donkey is only significant because he carries Christ. Likewise the priest: his significance is that he carries Christ within him. So when someone comes up and asks the priest's blessing, we're not kissing the hand of the priest, we're kissing the hand of Christ.