means,
To make holy; to purify from sin; to cleanse from corruption; to separate or set apart for the service and worship of God.
Also: Holy; physically and morally blameless; separate, or set apart for the service and worship of God.

Sanctify them through thy truth: thy word is truth. As thou hast sent me into the world, even so have I also sent them into the world. And for their sakes I sanctify myself, that they also might be sanctified through the truth.
John 17:17-19

Jesus was the pure and perfect Lamb of God; He did not need to be purified from sin, or cleansed from corruption, as we do.