Thirukkural

கடனறிந்து காலங் கருதி இடனறிந்து எண்ணி உரைப்பான் தலை.

Katanarindhu Kaalang Karudhi Itanarindhu Enni Uraippaan Thalai

He is chief (among ambassadors) who understands the proper decorum (before foreign princes), seeks the (proper) occasion, knows the (most suitable) place, and delivers his message after (due)