Kural - 537

Though things are arduous deemed, there's nought may not be won,
When work with mind's unslumbering energy and thought is done

Explanation
There is nothing too difficult to be accomplished, if a man set about it carefully, with unflinching endeavour.

Tamil Transliteration
Ariyaendru Aakaadha Illaipoch Chaavaak
Karuviyaal Potrich Cheyin.