Kural - 491

Begin no work of war, depise no foe,
Till place where you can wholly circumvent you know

Explanation
Let not (a king) despise (an enemy), nor undertake any thing (against him), until he has obtained (a suitable) place for besieging him.

Tamil Transliteration
Thotangarka Evvinaiyum Ellarka Mutrum
Itanganta Pinal Ladhu.