Sirach 10:13
Ben Sira, Ecclesiasticus11 For when one is dead he inherits maggots and vermin and worms. 12 The beginning of human pride is to forsake the Lord; the heart has withdrawn from its Maker. 13 For the beginning of pride is sin, and the one who clings to it pours out abominations. Therefore the Lord brings upon them unheard-of calamities, and destroys them completely. 14 The Lord overthrows the thrones of rulers, and enthrones the lowly in their place. 15 The Lord plucks up the roots of the nations, and plants the humble in their place.
Augustine City of God 14.13
On the City of God Against the PagansOur first parents fell into open disobedience because already they were secretly corrupted; for the evil act had never been done had not an evil will preceded it. And what is the origin of our evil will but pride? For pride is the beginning of sin. And what is pride but the craving for undue exaltation? And this is undue exaltation, when the soul abandons Him to whom it ought to cleave as its end, and becomes a kind of end to itself. This happens when it becomes its own satisfaction. And it does so when it falls away from that unchangeable good which ought to satisfy it more than itself.
Notes and References
"... Within early Christianity, the Letter of Barnabas echoes Sirach 5:12–14 about the danger of a double tongue, as well as the warning in Sirach 4:31 against an ungenerous attitude (Barnabas 19:7–9). Origen (d. 254 ce) quotes Ben Sira as scriptural when commenting on several Old Testament passages (Genesis 12:5; Joshua 15:6; Jeremiah 16:6). Clement of Alexandria (d. 215 CE) quotes about eighty Sirach verses, while John Chrysostom (d. 407 CE) includes about three hundred citations from the book. Augustine (d. 430 CE) not only cites Sirach about 300x, but also preached sermons on Sirach passages. Rabanus Maurus (d. 856 CE), abbot of Fulda in Germany, composed the earliest surviving Latin commentary on Sirach ..."
Corley, Jeremy "Sirach" in Oegema, Gerbern S. (ed.) The Oxford Handbook of the Apocrypha (pp. 284-305) Oxford University Press, 2021