Kural - 218

E'en when resources fall, they weary not of 'kindness due,'-
They to whom Duty's self appears in vision true

Explanation
The wise who know what is duty will not scant their benevolence even when they are without wealth.

Tamil Transliteration
Itanil Paruvaththum Oppuravirku Olkaar
Katanari Kaatchi Yavar.