Discourse on Psalm 23 (fragment) — Ante-Nicene Fathers, vol. 5 (S. D. F. Salmond, 1886) (public domain)
From the Commentary by the Holy Bishop and Martyr Hippolytus, on “The Lord is My Shepherd.”
And, moreover, the ark made of imperishable wood was the Saviour Himself. For by this was signified the imperishable and incorruptible tabernacle of (the Lord) Himself, which gendered no corruption of sin. For the sinner, indeed, makes this confession: “My wounds stank, and were corrupt, because of my foolishness.” But the Lord was without sin, made of imperishable wood, as regards His humanity; that is, of the virgin and the Holy Ghost inwardly, and outwardly of the word of God, like an ark overlaid with purest gold.
Reproduced in full. Translation: Ante-Nicene Fathers, vol. 5 (S. D. F. Salmond, 1886) (Public domain).
Why Pitre cites it
Christ's humanity described as the Ark: 'incorruptible wood, that is to say, of the Virgin and the Holy Spirit, overlaid within and without by purest gold of the word of God.' Pitre's Roman witness that Mary as Ark implies the divinity of her Son.
Notes
This is the whole ANF fragment 'On Psalm XXII or XXIII' (from the commentary on 'The Lord is my shepherd'), with its heading line. ANF wording: 'the Lord was without sin, made of imperishable wood, as regards His humanity; that is, of the virgin and the Holy Ghost inwardly, and outwardly of the word of God, like an ark overlaid with purest gold' — same sense as the key phrase, but the key phrase is a different (modern) rendering.