John 9:21 (KJV) says, "But by what means he now seeth, we know not; or who hath opened his eyes, we know not: he is of age; ask him: he shall speak for himself."

This verse is part of the story of the healing of the man born blind, which is found in the Gospel of John, specifically in chapter 9. This story is a powerful illustration of Jesus' ability to bring sight to the blind, both physically and spiritually. It is a significant moment in the Gospel as it leads to a confrontation between Jesus and the religious leaders of the time.

In this particular verse, we see the reaction of the parents of the man who had been blind, after he had been questioned by the Pharisees about how he had received his sight. The parents were aware that their son had been blind from birth, and they confirm that he had indeed been blind, but they do not know how he was healed. They defer to their son, saying that he is of age and capable of speaking for himself.

One of the key themes of this verse is the idea of personal testimony. The parents were unwilling to speak on behalf of their son, leaving him to speak for himself. This illustrates the idea that each individual is responsible for their own faith and relationship with God. This idea is reinforced throughout the Bible, particularly in the New Testament, where individuals are repeatedly called to give an account for their own actions and beliefs. It also highlights the importance of personal experience and the power of a personal testimony in sharing the message of Jesus.

The verse also speaks to the concept of spiritual blindness. While the man had been physically blind from birth, his healing also served as a metaphor for the spiritual blindness that many people experience. The Pharisees, who were spiritually blind to Jesus' identity and power, questioned the man and his parents, lacking the ability to see the truth of Jesus' miraculous works. This serves as a warning to all believers to avoid spiritual blindness and to seek the truth of Jesus' teachings.

In a broader context, this verse also serves as a reminder of the power and authority of Jesus. The healing of the blind man was a miraculous sign of Jesus' divinity, and it led to a confrontation between Jesus and the religious leaders. This ultimately revealed the depth of their spiritual blindness and their refusal to acknowledge Jesus as the Messiah. The blind man's testimony, which is all the more powerful because he had been healed, points to the authority of Jesus' teachings and the transformative power of his actions.

In terms of symbolism, the healing of the blind man can be seen as a symbol of the spiritual enlightenment that comes from having faith in Jesus. The blind man's physical sight was restored, but it also led to his spiritual sight being opened. This can be seen as a symbol of the spiritual sight that is granted to those who believe in Jesus. The willingness of the blind man to testify on his own behalf can also be seen as a symbol of the courage and conviction that comes with a deep faith in Jesus.

Overall, John 9:21 is a powerful verse that speaks to the themes of personal testimony, spiritual blindness, the authority of Jesus, and the transformative power of faith. It serves as a reminder of the importance of personal belief and the need to be diligent in seeking the truth of Jesus' teachings. It also serves as a symbol of the spiritual enlightenment and transformation that comes from having faith in Jesus.