Kural - 1051

When those you find from whom 'tis meet to ask,- for aid apply;
Theirs is the sin, not yours, if they the gift deny

Explanation
If you meet with those that may be begged of, you may beg; (but) if they withhold (their gift) it is their blame and not yours.

Tamil Transliteration
Irakka Iraththakkaark Kaanin Karappin
Avarpazhi Thampazhi Andru.