Kural - 450

Than hate of many foes incurred, works greater woe
Ten-fold, of worthy men the friendship to forego

Explanation
It is tenfold more injurious to abandon the friendship of the good, than to incur the hatred of the many.

Tamil Transliteration
Pallaar Pakai Kolalir Paththatuththa Theemaiththe
Nallaar Thotarkai Vital.