7 This sacrament of unity, this bond of a concord inseparably cohering, is set forth where in the Gospel the coat of the Lord Jesus Christ is not at all divided nor cut, but is received as an entire garment, and is possessed as an uninjured and undivided robe by those who cast lots concerning Christ's garment, who should rather put on Christ. Holy Scripture speaks, saying, “But of the coat, because it was not sewed, but woven from the top throughout, they said one to another, Let us not rend it, but cast lots whose it shall be.” That coat bore with it an unity that came down from the top, that is, that came from heaven and the Father, which was not to be at all rent by the receiver and the possessor, but without separation we obtain a whole and substantial entireness.
He cannot possess the garment of Christ who parts and divides the Church of Christ. On the other hand, again, when at Solomon's death his kingdom and people were divided, Abijah the prophet, meeting Jeroboam the king in the field, divided his garment into twelve sections, saying, “Take you ten pieces; for thus says the Lord, Behold, I will rend the kingdom out of the hand of Solomon, and I will give ten sceptres unto you; and two sceptres shall be unto him for my servant David's sake, and for Jerusalem, the city which I have chosen to place my name there.” As the twelve tribes of Israel were divided, the prophet Abijah rent his garment.
But because Christ's people cannot be rent, His robe, woven and united throughout, is not divided by those who possess it; undivided, united, connected, it shows the coherent concord of our people who put on Christ. By the sacrament and sign of His garment, He has declared the unity of the Church.
Source: The Treatises of Cyprian (New Advent)