“Then the soldiers, when they had crucified Jesus, took his garments, and made four parts, to every soldier a part; and also his coat: now the coat was without seam, woven from the top throughout.”
When the soldiers had crucified Jesus, they took his garments and divided them into four parts, one for each soldier. Also his tunic; now the tunic was seamless, woven in one piece from the top. — The soldiers' division of Jesus' garments among four executioners (Roman custom) fulfills Psalm 22:18 ("they divide my clothes among them"). The especial attention to the seamless tunic (chiton araphos, woven as one unbroken piece) emphasizes wholeness and perhaps priestly significance—the high priest's robe was seamless (Exodus 39:22). Jesus' tunic's indivisibility symbolizes the unity of his person and priesthood.
Church Fathers on John 19:23
The Evangelist describes the tunic, to show that it was of an inferior kind, the tunics commonly worn in Palestine being made of two pieces.
Others say that they did not weave in Palestine, as we do, the shuttle being driven upwards through the warp; so that among them the woof was not carried upwards but downwards.
They said therefore among themselves, Let us not rend it, but cast lots for it whose it should be. It seems then that the other garments were made up of equal parts, as it was not necessary to rend them; the tunic only having to be rent in order to give each an equal share of it; to avoid which they preferred casting lots for it, and one having it all. This answered to the prophecy: That the Scripture might be fulfilled which says, They parted My raiment among them, and for…