The king noticed one man without a wedding garment. His presence, or lack thereof, speaks volumes about his heart.
The man at the wedding feast wasn't just accidentally underdressed. He actively refused or neglected the provided attire.
Think about it: he was invited, he came, but he chose not to conform to the host's expectations. This wasn't a minor oversight; it was a profound insult to the king. It showed a lack of respect for the occasion and, more importantly, for the one hosting it.
In the spiritual sense, this represents someone who professes to follow Christ but refuses to 'put on' the righteousness and transformation that comes from Him. It's choosing our own way, our own 'filthy rags' of self-righteousness, over the perfect 'garment' of Christ's imputed righteousness and the Holy Spirit's work in our lives. It's a rejection of God's provision and a subtle, yet serious, disrespect for His Kingly authority.