Friend - Rather, "companions." The word does not imply friendship.
He was speechless - He had no excuse. So it will be with all hypocrites.

He saith unto him, Friend - Rather, companion: so εταιρε should be translated. As this man represents the state of a person in the visible Church, who neglects to come unto the master of the feast for a marriage garment, for the salvation which Christ has procured, he cannot be with any propriety called a friend, but may well be termed a companion, as being a member of the visible Church, and present at all those ordinances where Christ's presence and blessing are found, by all those who sincerely wait upon him for salvation.
How camest thou in hither - Why profess to be called by my name while living without a preparation for my kingdom?
He was speechless - Εφιμωθη, he was muzzled, or gagged. He had nothing to say in vindication of his neglect. There was a garment provided, but he neither put it on, nor applied for it. His conduct, therefore, was in the highest degree insulting and indecorous. As this man is the emblem, by general consent, of those who shall perish in the last day, may we not ask, without offense, Where does the doctrine of absolute reprobation or preterition appear in his case? If Christ had never died for him, or if he had applied for the garment, and was refused, might he not well have alleged this in behalf of his soul? - and would not the just God have listened to it? But there is not the smallest excuse for him: Christ died, the sacrifice was offered, for him; the ministers of the Gospel invited him; the Holy Spirit strove with him; he might have been saved, but he was not: and the fault lies so absolutely at his own door that the just God is vindicated in his conduct, while he sends him to hell, not for the lack of what he could not get, but for the lack of what he might have had, but either neglected or refused it.
Then said the king to the servants - To the ministering angels, executors of the Divine will.
Cast him into outer darkness - The Jewish marriages were performed in the night season, and the hall where the feast was made was superbly illuminated; the outer darkness means, therefore, the darkness on the outside of this festal hall; rendered still more gloomy to the person who was suddenly thrust out into it from such a profusion of light. See all this largely treated of on Matthew 8:12 (note).

And he saith unto him, Friend, how camest thou in hither not having a wedding garment? And he was (d) speechless.
(d) Literally, "haltered", that is to say, he held his peace, as though he had a bridle or a halter around his neck.

And he saith unto him, friend,.... Either in an ironical way, or because he professed to be a friend of God and Christ:
how camest thou in hither, not having a wedding garment? Which way didst thou come in hither? since he did not come in by faith, in the righteousness of Christ; intimating, that he climbed up some other way, and was a thief and robber; or with what face, or how couldest thou have the assurance to come in hither in such a dress, having nothing but the filthy rags of thine own righteousness? How couldest thou expect to meet with acceptance with me, or to be suitable company for my people, not being arrayed with the garments of salvation, and robe of righteousness, as they are?
And he was speechless: or muzzled: his mouth was stopped, he had nothing to say for himself: not but that there will be pleas made use of by hypocrites, and formal professors, another day; who will plead either their preaching and prophesying in Christ's name; or their attendance on outward ordinances; or the works they have done, ordinary or extraordinary; but then these will all be superseded and silenced, their own consciences will condemn them, their mouths will be stopped, and they will have nothing to say in vindication of themselves; their righteousness will not answer for them in a time to come. The Jews have a tradition (l), that
"Esau the wicked, will veil himself with his garment, and sit among the righteous in paradise, in the world to come; and the holy blessed God will draw him, and bring him out from thence, which is the sense of those words, Obadiah 1:4. "Though thou exalt thyself as the eagle, and though thou set thy nest among the stars, thence will I bring thee down, saith the Lord."''
(l) T. Hieros. Nedarim, fol. 38. 1.

Friend, how camest thou in hither, not having a wedding garment? And he was speechless--being self-condemned.

How camest thou in hither not having a wedding garment? The fact that he had not was proof that he had no right to be there. All invited might be very different before, good and bad, but they must be clothed alike when the guests of the Lord.

A wedding garment - The righteousness of Christ, first imputed, then implanted. It may easily be observed, this has no relation to the Lord's Supper, but to God's proceeding at the last day.