Kural - 782

Friendship with men fulfilled of good Waxes like the crescent moon;
Friendship with men of foolish mood, Like the full orb, waneth soon

Explanation
The friendship of the wise waxes like the new moon; (but) that of fools wanes like the full moon.

Tamil Transliteration
Niraineera Neeravar Kenmai Piraimadhip
Pinneera Pedhaiyaar Natpu.