25 Those who find fault with the prophets, accusing them of adultery for instance, in actions which are above their comprehension, are like those Pagans who profanely charge Christ with folly or madness because He looked for fruit from a tree out of the season; or with childishness, because He stooped down and wrote on the ground, and, after answering the people who were questioning Him, began writing again. Such critics are incapable of understanding that certain virtues in great minds resemble closely the vices of little minds, not in reality, but in appearance.
Such criticism of the great is like that of boys at school, whose learning consists in the important rule, that if the nominative is in the singular, the verb must also be in the singular; and so they find fault with the best Latin author, because he says, Pars in frusta secant. He should have written, say they, secat. And again, knowing that religio is spelt with one l, they blame him for writing relligio, when he says, Relligione patrum. Hence it may with reason be said, that as the poetical usage of words differs from the solecisms and barbarisms of the unlearned, so, in their own way, the figurative actions of the prophets differ from the impure actions of the vicious.
Accordingly, as a boy guilty of a barbarism would be whipped if he pled the usage of Virgil; so any one quoting the example of Abraham begetting a son from Hagar, in defence of his own sinful passion for his wife's handmaid, ought to be corrected not by caning only, but by severe scourging, that he may not suffer the doom of adulterers in eternal punishment. This indeed is a comparison of great and important subjects with trifles; and it is not intended that a peculiar usage in speech should be put on a level with a sacrament, or a solecism with adultery.
Still, allowing for the difference in the character of the subjects, what is called learning or ignorance in the proprieties and improprieties of speech, resembles wisdom or the want of it in reference to the grand moral distinction between virtue and vice.
Source: Reply to Faustus the Manichaean (New Advent)