Jesus tells Mary not to hold on to him, because he has not yet ascended into heaven. Although some commentators make this passage to be primarily about the form of Jesus’ resurrected body, that it ought not be touched before the ascension, this is problematic given all the physicality of so many other Resurrection scenes. Thomas is invited to touch Jesus’ wounds. Jesus eats with the disciples. He breathes on them, without a caution “don’t touch!” There is a difference between not touching and not holding on.
The message Jesus gives to Mary seems more specifically oriented to her and to her spirituality. Mary and Jesus had a close friendship but Jesus is telling her already that he is going to leave in a sense, and ascend to his Father. Mary is probably eager at the Resurrection to go back to her old relationship with Jesus, to resume things and pick them up as if nothing had changed with death and resurrection. But Jesus already tells her that he will soon be ascending, i.e., more change is on the way. This is part of Jesus’ missioning of Mary: she’s being asked not to cling to a previous way of relating to Jesus but rather to focus on spreading the good news. Of course, this does not mean that she is not to love Jesus or relate to him, but the nature of that relationship will change.
This idea of not clinging is relevant to so many aspects of spiritual life. Perhaps a person is being invited to pray or to relate to God in a new way, after old models of prayer or pictures of God no longer suffice for one’s new circumstances. Or a relationship may change and a new way of entering into that relationship may be the invitation. Or we may be past focused when Jesus is inviting us to be present focused in our mission.
Jesus’ words not to touch him is not a rebuke but an invitation, an invitation to new life for Mary in her mission, as he sends her off to the other disciples.