Mahāsutasomajātaka

Suttapiṭaka · Khuddakanikāya · Jātaka (2) · Vol. 28 · Section 336

[336] One whose virtue (sīla) is pure should choose death rather than life as one censured, of evil character; for that for whose sake he might speak falsehood does not protect that man from bad destinations. Even if the wind should carry off the mountain, even if the moon and the sun should fall to the earth, and all the rivers should run against the stream, never, O King, would I speak a lie.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.