Succajjātaka

Suttapiṭaka · Khuddakanikāya · Jātaka (1) · Vol. 27 · Section 579

[579] One should speak only of what one would do; what one would not do, that one should not speak of. The wise thoroughly recognize one who speaks without acting.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.