Pindar, Pythian Odes
4.272-273 (tr. John Sandys):
For, even for the feeble, it is an easy task to shake a city to its foundation,
but it is indeed a sore struggle to set it in its place again.
ῥᾴδιον μὲν γὰρ πόλιν σεῖσαι καὶ ἀφαυροτέροις·
ἀλλ' ἐπὶ χώρας αὖτις ἕσσαι δυσπαλὲς
Commentators compare Theognis 845-846 (tr. Dorothea Wender):
A man's good luck can easily be spoiled;
But to improve bad luck is difficult.
εὖ μὲν κείμενον ἄνδρα κακῶς θέμεν εὐμαρές ἐστιν,
εὖ δὲ θέμεν τὸ κακῶς κείμενον ἀργαλέον.
485 ἄνδρα codd: ἄστυ Bergk
Or, if Bergk's conjecture is adopted:
A town in a good condition is easy to destroy,
but it is hard to set aright one in a bad condition.
Related post: Easier to Tear Down Than to Build