Kural - 638

'Tis duty of the man in place aloud to say
The very truth, though unwise king may cast his words away

Explanation
Although the king be utterly ignorant, it is the duty of the minister to give (him) sound advice.

Tamil Transliteration
Arikondru Ariyaan Eninum Urudhi
Uzhaiyirundhaan Kooral Katan.