While he was still speaking, behold, Judas, one of the twelve, came, and with him a great multitude with swords and clubs, from the chief priest and elders of the people.
Now he who betrayed him gave them a sign, saying, "Whoever I kiss, he is the one. Seize him." Immediately he came to Jesus, and said, "Hail, Rabbi!" and kissed him.
Jesus said to him, "Friend, why are you here?" Then they came and laid hands on Jesus, and arrested him.
Matthew 26,47