Valmiki Ramayana Kishkindha Kanda Sarga 30 Shloka 73

कृतार्थाः one who has achieved his objective, ये whoever, अकृतार्थानाम् of the needy man, मित्राणाम् to the friends, न भवन्ति not help, मृतान् after death, कृतघ्नान् ungrateful people, तान् them, क्रव्यादाः अपि even by carnivorous animals, न उपभुञ्जते not like to eat.

'Even the carnivorous animals dislike to eat the body of such ungrateful men who do not help their friends even though they have received help and have achieved their objective.'