Kural - 807

True friends, well versed in loving ways,
Cease not to love, when friend their love betrays

Explanation
Those who have (long) stood in the path of affection will not give it up even if their friends cause (them) their ruin.

Tamil Transliteration
Azhivandha Seyyinum Anparaar Anpin
Vazhivandha Kenmai Yavar.