SB 7.10.30
sri-bhagavan uvaca
maivam vibho ’suranam te
pradeyah padma-sambhava
varah krura-nisarganam
ahinam amrtam yatha
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Personality of Godhead replied: My dear Lord Brahma, O great lord born from the lotus flower, just as it is dangerous to feed milk to a snake, so it is dangerous to give benedictions to demons, who are by nature ferocious and jealous. I warn you not to give such benedictions to any demon again.