Hāritattheragāthā
“Yo pubbe karaṇīyāni, pacchā so kātumicchati; Sukhā so dhaṁsate ṭhānā, pacchā ca manutappati.
Hārita (2nd)
Whoever wishes to do afterwards tasks they should have done before has lost the causes for happiness, and afterwards they’re tormented by regrets.