John 13:27

John 13:27 "What you are going to do, do quickly."(ESV)
Why does Jesus say this? I would imagine a human being saying something along the lines of "Please Don't do that." But Jesus is doing the opposite, he is giving authority to betray him. Is this this to fulfill the Scriptures?
Then You have Judas which Betrays Jesus on His authority, so in that sense, he isn't betraying him, but taking orders.

I'm posting this for my understanding, and others as God sees fit. This is not to confuse anyone in there faith.

Please, if at all possible, use scripture to back up views. :)