Jerome : (Verse 5.) For it is a day of slaughter, and of trampling, and of weeping to the Lord God of hosts in the Valley of Vision. He reveals the reasons according to triple understanding why he said: Depart from me, I will weep bitterly; because Zion is trodden down, once a mountain of visions, and now a valley of weeping. — Commentary on Isaiah Jerome : (Verse 5.) For it is a day of slaughter and treading down, and of weeping from the Lord God of hosts in the valley of vision, searching the wall, and magnifying upon the mountain. LXX: For it is a day of tumult, and of destruction, and of treading down, and of error from the Lord God of hosts in the valley of Zion; they wander about from the least to the greatest: they are wandering upon the mountains. For the Day of Judgment and slaughter and trampling shall never come to Jerusalem, which is interpreted as the vision of peace; but to the ancient name Jebus, which is interpreted as trampling. And also tears or errors, as the Seventy have translated from the Lord of hosts, not that tears and errors are from the Lord; but by the occasion of the holy Scriptures, which the Lord has given to be read, occasions of error are born to those who can say: Why have you made us to err from your ways? (Isa. LXIII, 27). And in another place: The Lord mixed for them the spirit of error (Ibid. XXIX, 10): so that they would not stand on the mountain of Vision, but in the valley of Zion. But this very day, which rises in the valley of Vision from the Lord of hosts, examines the wall of the heretics, which they have constructed against the Church as the strongest defense; and also the magnificent and glorious, that is, their teachers, who boast of standing on the mountain of Christ. We read elsewhere: Come, let us go up to the mountain of the Lord, and to the house of the God of Jacob: and he will instruct us in his ways (Isaiah 2:3). Moreover, what the Seventy translated, they err from the minimum to the maximum, they err over the mountains. We should understand that they are in a greater sin, who are greater, and yet all err from the minimum to the maximum, and err over the mountains: Moses, Jeremiah, and the other prophets, the evangelists and apostles. And when they are in the valley, they wander astonishingly in the mountains. — Commentary on Isaiah