Donatus, Vita Vergilii
“Asconius Pedianus wrote a book against Vergil’s detractors, but he nevertheless adds some objections of his own, mostly dealing with Vergil’s narration and the fact that he had taken much from Homer. But he also says that Vergil was accustomed to refute this latter criticism thus: ‘Why did they themselves not try to do take some verses from Homer? To be sure, they would learn that it easier to take Hercules’ club than to lift a verse from Homer.’ Yet, Asconius adds that he decided to retire so that he could do everything to the satisfaction of his malicious critics.”
Asconius Pedianus libro, quem contra obtrectatores Vergiliis scripsit, pauca admodum obiecta ei proponit eaque circa historiam fere et quod pleraque ab Homero sumpsisset; sed hoc ipsum crimen sic defendere adsuetum ait: cur non illi quoque eadem furta temptarent? Verum intellecturos facilius esse Herculi clavam quam Homero versum subripere”; et tamen destinasse secedere ut omnia ad satietatem malevolorum decideret.