From 40 Questions About Christians and Biblical Law by Tom Schreiner, as part of the answer to the question, What is the Role of the Law in the Gospel of Mark?
The law no longer occupies the same status now that Christ has come. In the Old Testament anyone who touched a leper became unclean. Lepers were to reside outside the camp so that they would not infect others with their uncleanness (Lev. 13:46). Jesus’ healing of the leper, then, in Mark 1:40-45 is quite striking. Indeed, Jesus cleansed him by touching him (v. 41). Jesus could have cleansed him with a pronouncement, as he did on many other occasions. In fact, Jesus could have taken precautions to avoid touching the leper in order to avoid contact with the unclean, so that he himself would not be ritually defiled, for in the Old Testament one who touches what is unclean becomes unclean. But the new order inaugurated by Jesus is evident here, for when Jesus touched the unclean leper, Jesus was not defiled by uncleanness. Instead the leper became clean. In Jesus the power of the holy was such that his holiness consumed and destroyed the uncleanness of the leper. The story suggests that Jesus is greater than the Old Testament law, that the law points to him and is fulfilled in him.
We see something similar in Mark 5:24-43, where Jesus healed the woman who had a hemorrhage of blood for twelve years and raised a twelve-year-old girl from the dead. Mark emphasized that the woman touched Jesus, calling attention to it four times. (vv. 27, 28, 30, 31). The Old Testament clearly teaches that a woman who has a discharge of blood is unclean so that anything or anyone who touches her becomes unclean (Lev. 15:25-27). So it is quite striking that she touched Jesus. But again the power of the holy overwhelms and conquers and irradiates her uncleanness. Instead of Jesus becoming unclean, his touch made her clean. The old rules do not apply in the same way in the case of Jesus. The Old Testament also teaches that one who touches the dead is rendered unclean (cf. Lev. 21:1, 11; 22:4; Num. 5:2). But again, when Jesus approached Jairus’s dead daughter, he took her by the hand (Mark 5:41). Instead of contracting the uncleanness from a corpse, Jesus cleansed her and granted her new life by raising her from the dead. These accounts suggest that the law is no longer central with the coming of the Christ. Jesus’ healings and his raising of the dead show that the new age has arrived in his ministry.
To sum up in one sentence the point made in these two paragraphs,
Now that Christ has come, the purity laws are fulfilled in him, signified by his healing of the leper, his touching of the woman with the flow of blood, and his healing touch of Jairus’s daughter.
I almost finished this book while I was travelling, so I may be posting a review of it soon. If I can ever get on top of things in real life, that is.