Kural - 466

'Tis ruin if man do an unbefitting thing;
Fit things to leave undone will equal ruin bring

Explanation
58 He will perish who does not what is not fit to do; and he also will perish who does not do what it is fit to.

Tamil Transliteration
Seydhakka Alla Seyak Ketum Seydhakka
Seyyaamai Yaanung Ketum.