Kural - 666

Whate'er men think, ev'n as they think, may men obtain,
If those who think can steadfastness of will retain

Explanation
If those who have planned (an undertaking) possess firmness (in executing it) they will obtain what they have desired even as they have desired it.

Tamil Transliteration
Enniya Enniyaangu Eydhu Enniyaar
Thinniyar Aakap Perin.