Mat 22:13 Then the king said to the servants, Bind him hand and foot, and take him away, and cast [him] into outer darkness; there shall be weeping and gnashing of teeth.

The fate of the ill-dressed wedding guest also follows three parts following the pattern of physical, emotional, and intellectual. Being bound is the physical part. Being taken away is the emotional. Being cast into the darkness is the mental part. Darkness is a Greek (and Christ's) metaphor for ignorance.

The "binding" of the guest raises a question of freedom. The invited guest were free to reject the invitation. They were not killed except when they first killed the messengers. The guests from the highways were also free to come and free to dress appropriately

As I explain in a more detailed post, my sense is that Christ uses the phrase "weeping and gnashing of teeth" in same dramatic and almost humorous way that that we say in English "whining and complaining" or "bitching and moaning." The "gnashing of teeth" could indicate the chattering of teeth, conveying the sense that this person is tossed out "in the cold," except that Christ uses this same phrase earlier to describe weeds cast into a fire.

"Servants" is not the usual doulos, ("slave" used earlier in the parable, but diakonos, which is translated in an earlier verse as "minister," from the noun diakonos, which means "servant," "messenger," and "attendant." This is the source for our word "deacon." As a verb, it is from diakoneô, which "to act as a servant," "to minister," and "to perform services." To me, this means that there are two groups of servant: a larger group that took the message to the guest and a special, smaller group that takes the bad guest outside.

"Bind" is from deô, means "to tie," "to bind," "to fetter," and "to keep in bonds." It is a metaphor for chaining. This is the term used earlier for "binding on earth is bound in heaven."
"Take away" is from airo, which primarily means "to lift," and also means "to raise up," "to take up," "to raise a child," "to exalt," "to lift and take away," and "to remove."

"Caste out" is from ekballô and means "throw out," "cast out of a place,"and "expose." Ek means "out of," "from," and "away from." Ballo is "to throw" or "to scatter." The general idea of ballo is "to throw without caring where something falls," so it isn't like putting something into a specific place.

"Darkness" is from skotos, which means "darkness," "gloom," "blindness," and "dizziness." It is a metaphor in Greek for ignorance.

"Weeping" is from klauthmos which means "a weeping."

"Gnashing" is from brugmos , which means "biting," "gobbling," and "chattering."