Kural - 647

Mighty in word, of unforgetful mind, of fearless speech,
'Tis hard for hostile power such man to overreach

Explanation
It is impossible for any one to conquer him by intrique who possesses power of speech, and is neither faulty nor timid.

Tamil Transliteration
Solalvallan Sorvilan Anjaan Avanai
Ikalvellal Yaarkkum Aridhu.