SB 4.14.10

aher iva payaḥ-poṣaḥ
 poṣakasyāpy anartha-bhṛt
venaḥ prakṛtyaiva khalaḥ
 sunīthā-garbha-sambhavaḥ
Word for word: 
aheḥ — of a snake; iva — like; payaḥ — with milk; poṣaḥ — the maintaining; poṣakasya — of the maintainer; api — even; anartha — against the interest; bhṛt — becomes; venaḥ — King Vena; prakṛtyā — by nature; eva — certainly; khalaḥ — mischievous; sunīthā — of Sunīthā, Vena’s mother; garbha — the womb; sambhavaḥ — born of.
Translation: 
The sages began to think within themselves: Because he was born from the womb of Sunīthā, King Vena is by nature very mischievous. Supporting this mischievous king is exactly like maintaining a snake with milk. Now he has become a source of all difficulties.
Purport: 

Saintly persons are generally aloof from social activities and the materialistic way of life. King Vena was supported by the saintly persons just to protect the citizens from the hands of rogues and thieves, but after his ascendance to the throne, he became a source of trouble to the sages. Saintly people are especially interested in performing sacrifices and austerities for the advancement of spiritual life, but Vena, instead of being obliged because of the saints’ mercy, turned out to be their enemy because he prohibited them from executing their ordinary duties. A serpent who is maintained with milk and bananas simply stores poison in his teeth and awaits the day to bite his master.