Kural - 715

Midst all good things the best is modest grace,
That speaks not first before the elders' face

Explanation
The modesty by which one does not rush forward and speak in (an assembly of) superiors is the best among all (one's) good qualities.

Tamil Transliteration
Nandrendra Vatrullum Nandre Mudhuvarul
Mundhu Kilavaach Cherivu.