Kural - 619

Though fate-divine should make your labour vain;
Effort its labour's sure reward will gain

Explanation
Although it be said that, through fate, it cannot be attained, yet labour, with bodily exertion, will yield its reward.

Tamil Transliteration
Theyvaththaan Aakaa Theninum Muyarsidhan
Meyvaruththak Kooli Tharum.