One to the Lord, One Let Go: The Two Goats of the Atonement and the Two Men Before Pilate
Old Testament: Leviticus 16:7-9, 21-22
He shall make the two buck goats to stand before the Lord in the door of the tabernacle of the testimony: And casting lots upon them both, one to be offered to the Lord, and the other to be the emissary goat: That whose lot fell to be offered to the Lord, he shall offer for sin: ... And putting both hands upon his head, let him confess all the iniquities of the children of Israel, and all their offences and sins: and praying that they may light on his head, he shall turn him out by a man ready for it, into the desert. And when the goat hath carried all their iniquities into an uninhabited land, and shall be let go into the desert,
Old Testament, also: Leviticus 16:27
But the calf and the buck goat, that were sacrificed for sin, and whose blood was carried into the sanctuary, to accomplish the atonement, they shall carry forth without the camp, and shall burn with fire.
New Testament: Matthew 27:16, 21, 26; Hebrews 13:11-13
And he had then a notorious prisoner, that was called Barabbas. ... And the governor answering, said to them: Whether will you of the two to be released unto you? But they said, Barabbas. ... Then he released to them Barabbas, and having scourged Jesus, delivered him unto them to be crucified. ... For the bodies of those beasts, whose blood is brought into the holies by the high priest for sin, are burned without the camp. Wherefore Jesus also, that he might sanctify the people by his own blood, suffered without the gate. Let us go forth therefore to him without the camp, bearing his reproach.
The connection
Once a year two goats were set at the door of the tabernacle (alike in size and look, Tertullian says), and lots were cast over them. One lot fell "to be offered to the Lord", and that goat was killed and its blood carried into the holy place. The other was the emissary goat: the high priest laid both hands on its head, confessed over it all the sins of the people, and it was led away alive into the wilderness, carrying their iniquities into an uninhabited land (Leviticus 16:7-9, 21-22). Two goats, one death, one release, and one sin borne away between them. On the morning of the Passion two men stand side by side before a crowd, and a choice is made between them. "Whether will you of the two to be released unto you? But they said, Barabbas" (Matthew 27:21). The guilty man is let go, and the innocent is led away to die. The Epistle to the Hebrews sees the rest of the rite in the place of His death: the bodies of the sin offerings were burned outside the camp, "wherefore Jesus also, that he might sanctify the people by his own blood, suffered without the gate" (Hebrews 13:11-12). The Fathers read the pair as one figure. Pseudo-Jerome, on Mark's account of the Passion, is plainest: "Here are two goats; one is the scape goat, that is, one loosed and sent out ...; the other is slain, as a lamb, for the sins of those who are forgiven." Tertullian asks of the two goats, "of like size, and very similar in appearance", whether they "figure the two natures of Christ", and reads them of His two comings, the first in lowliness and the second in glory. Theodoret explains why a goat and not a lamb: "as sin He explains the figure of the sacrifice of the goats, for on behalf of sin, in the Law, a goat, and not a lamb, was offered."
Moral sense
The same Law that set the two goats at the door commanded the day itself: "you shall afflict your souls, and shall do no work", and on it came "the cleansing from all your sins" (Leviticus 16:29-31). The fast did not take the sin away; in figure the blood did that, though only Christ's Blood truly does, and the goat carried the sins into the desert. The fast was how a man owned that the sins confessed over that head were his. This is why the Church still fasts. Nobody is forgiven for skipping a meal. We fast to stop being spectators, and to say with the body what we have been saying with our lips. Isaias gives the test of a real fast: "loose the bands of wickedness ... let them that are broken go free". A fast that leaves a man harder on other people has missed the day, whose whole point was a burden carried away. And note the order: the confession came before the goat was sent out, the sins named aloud over its head and only then carried off. That is still where the sacrament's forgiveness begins, in naming them aloud to the priest.
Anagogical sense
Hebrews takes the rite outside the camp and tells us to follow: "Let us go forth therefore to him without the camp, bearing his reproach." The Christian's place is where the sin offering was burned, outside the city, which is why martyrs died outside the gates and why the Church is never at home in the world. At the end there is no wilderness left to carry anything into: the sins are gone, the accuser is cast out, and the only blood that is remembered is the Blood of the Lamb standing as slain.
The Fathers
Pseudo-Jerome, in the Catena Aurea on Mark 15: "Here are two goats; one is the scape goat, that is, one loosed and sent out ...; the other is slain, as a lamb, for the sins of those who are forgiven." Tertullian, Against Marcion III.7: "If I may offer, moreover, an interpretation of the two goats which were presented on the great day of atonement, do they not also figure the two natures of Christ?" Theodoret, Eranistes: "as sin He explains the figure of the sacrifice of the goats, for on behalf of sin, in the Law, a goat, and not a lamb, was offered."
Warrant
Patristic because the Gospels do not name Leviticus 16 at the trial; Hebrews 13:11-12 makes one half of the link itself, the sin offering burned outside the camp and Christ suffering outside the gate, which is scriptural. The pairing of the released goat with Barabbas is read by Pseudo-Jerome in the Catena Aurea on Mark 15, and the two goats are taken as a figure of Christ by Tertullian (Against Marcion III.7) and Theodoret (Eranistes). The Fathers do not agree on what the second goat stands for: Tertullian reads the two as the two advents of Christ, Pseudo-Jerome as Christ and Barabbas, and Theodoret only that a goat was offered because a goat was the offering for sin. The entry keeps all three rather than flattening them into one reading. The Douay's "emissary goat" is the Hebrew azazel, which the Vulgate renders caper emissarius, the goat sent out, and which later English calls the scapegoat.
Catechism of the Catholic Church, paragraph 615.
The verses
Leviticus 16:7 · Leviticus 16:8 · Leviticus 16:9 · Leviticus 16:21 · Leviticus 16:22 · Leviticus 16:27 · Matthew 27:16 · Matthew 27:21 · Matthew 27:26 · Hebrews 13:11 · Hebrews 13:12 · Hebrews 13:13