Letters 108.34

Next, he congratulates himself on finding the source of Vergil’s words:

Over whose head the mighty gate of Heaven Thunders,

remarking that Ennius stole the idea from Homer, and Vergil from Ennius. For there is a couplet by Ennius, preserved in this same book of Cicero’s, On the State:

If it be right for a mortal to scale the regions of Heaven, Then the huge gate of the sky opens in glory to me.

Seneca, Letters to Lucilius 108.34, translated by Richard Mott Gummere