Ramayana
वरप्रदानसम्मूढो मान्या ऽमान्यान् स दुर्मतिः । न वेत्ति मम शापाच्च प्रकृतिं दारुणां गतः ॥ 7-11-40 ॥
"That evil-minded one, deluded by the granting of the boon, does not distinguish the honorable from the dishonorable; and by my curse he has come to a cruel nature."
english translation