Jesus saith unto her, Touch me not; for I am not yet ascended to my Father: but go to my brethren, and say unto them, I ascend unto my Father, and your Father; and to my God, and your God.
Jesus tells the woman not to touch him because he hasn't gone back to his Father yet. He asks her to tell his brothers that he is going to his Father, who is also their Father, and that his God is their God too.