Caesar, Gallic War
1.14 (tr. H.J. Edwards):
For it was the wont of the immortal gods to grant a temporary prosperity and a longer impunity to make men whom they purposed to punish for their crime smart the more severely from a change of fortune.
Consuesse enim deos immortales, quo gravius homines ex commutatione rerum doleant, quos pro scelere eorum ulcisci velint, his secundiores interdum res et diuturniorem impunitatem concedere.
Commentators cite an anonymous fragment of tragedy preserved by Aristotle, Rhetoric
2.23.20 (1399 b; tr. John Henry Freese):
It is not from benevolence that the deity bestows great blessings upon many, but in order that they may suffer more striking calamities.
πολλοῖς ὁ δαίμων οὐ κατ᾽ εὔνοιαν φέρων
μεγάλα δίδωσιν εὐτυχήματ᾽, ἀλλ᾽ ἵνα
τὰς συμφορὰς λάβωσιν ἐπιφανεστέρας.
and Claudian, Against Rufinus
1.21-23 (tr. Maurice Platnauer):
No longer can I complain that the unrighteous man reaches the highest pinnacle of success. He is raised aloft that he may be hurled down in more headlong ruin.
iam non ad culmina rerum
iniustos crevisse queror; tolluntur in altum,
ut lapsu graviore ruant.