Kural - 819

E'en in a dream the intercourse is bitterness
With men whose deeds are other than their words profess

Explanation
The friendship of those whose actions do not agree with their words will distress (one) even in (one's) dreams.

Tamil Transliteration
Kanavinum Innaadhu Manno Vinaiveru
Solveru Pattaar Thotarpu.