Augustine of Hippo

It is evident, then, that the oldness of the letter, in the absence of the newness of the spirit, instead of freeing us from sin, rather makes us guilty by the knowledge of sin. Whence it is written in another part of Scripture, "He that increaseth knowledge, increaseth sorrow,"—not that the law is itself evil, but because the commandment has its good in the demonstration of the letter, not in the assistance of the spirit; and if this commandment is kept from the fear of punishment and not from the love of righteousness, it is …

On The Spirit And The Letter 26 ↗

Jerome

"For with much wisdom comes much grief, and he who increases knowledge increases pain." The more a man seeks wisdom, the more he finds himself in vice and far from those virtues, which he is seeking. For those who are powerful suffer torments more gravely [Cfr Sap. 6, 7.], and more is demanded of the man, to whom more is entrusted. Because of this he increases his pain who increases his knowledge, and is saddened by grief according to God, and suffers beyond his offences. …

Commentary on Ecclesiastes ↗

Bonaventure

"Because in much wisdom there is much indignation," either of contrition, against fault, or of impatience from pride, because great clerics, when they do not have what they want, are most easily indignant: whence it is said in Job thirty-two that Elihu was indignant, and this because he considered himself wise. And therefore it follows: "He who adds knowledge adds also sorrow," because an impatient man sustains many sorrows, since there is no one for whom all things turn out according to his wish. …

Commentary on Ecclesiastes, Chapter 1 ↗