Mark 5:42 (KJV) says, "And straightway the damsel arose, and walked; for she was of the age of twelve years. And they were astonished with a great astonishment."

This verse is part of the larger narrative of Mark 5, which tells the story of Jesus' miraculous healing of Jairus' daughter. In this chapter, Jairus, a synagogue leader, approaches Jesus and asks him to come and heal his daughter who is about to die. As Jesus and Jairus make their way to Jairus' home, a woman who had been suffering from a bleeding condition for twelve years comes up behind Jesus and touches his cloak, believing that she will be healed. Jesus feels power go out from him and stops to find out who touched him. The woman admits what she has done, and Jesus tells her that her faith has healed her. Then, messengers arrive to tell Jairus that his daughter has died, but Jesus tells him not to fear and to believe. When they arrive at the house, Jesus takes the girl by the hand and tells her to arise, and she does, astonishing all who witness it.

The miracle in Mark 5:42 is significant for several reasons. First, the girl's age of twelve is significant because it marks the threshold of adulthood in Jewish tradition. At the age of twelve, a Jewish girl would become responsible for following the commandments and participating in religious rituals. By healing a girl on the cusp of womanhood, Jesus is demonstrating his power over life and death and affirming the value and sanctity of human life, regardless of age. This theme of the sanctity of life is central to the teachings of Jesus and is a recurring theme throughout the Bible.

The astonishment of the witnesses also underscores the miraculous nature of the healing. The fact that the girl not only arose but also walked immediately after being brought back to life emphasizes the instantaneous and complete nature of Jesus' healing power. The language used to describe the witnesses' reaction, "they were astonished with great astonishment," emphasizes the extraordinary nature of the event and highlights the impact of Jesus' miraculous works on those who witnessed them. This emphasizes the theme of Jesus' divine authority and power over illness and death.

Contextually, this verse is part of a larger section of Mark's gospel that focuses on Jesus' demonstration of his power through various miraculous healings. The preceding verses of Mark 5 describe the healing of the woman with the issue of blood, and the following verses narrate the healing of the blind man. These stories collectively serve to emphasize the power and authority of Jesus and his ability to heal all manner of physical and spiritual afflictions. These miracles also underscore Jesus' compassion and concern for both the physical and spiritual well-being of those he encountered. The symbolism of these healings and the larger context of Jesus' miraculous works point to his identity as the Messiah and the Son of God.

In conclusion, Mark 5:42 is a powerful and pivotal verse in the larger narrative of Jesus' miraculous healings in Mark's gospel. The healing of Jairus' daughter at the age of twelve serves as a demonstration of Jesus' authority over illness and death, as well as a testament to the sanctity and value of human life. The astonishment of the witnesses and the larger context of Jesus' miraculous works emphasize his divinity and his compassion for those in need. Overall, this verse serves to strengthen the themes of Jesus' divine authority, compassion, and power over physical and spiritual afflictions, while also affirming the significance of faith and belief in experiencing the miraculous power of God.