PURPORT

At Hiranyaksa's last moment, his mother, Diti, remembered what her husband had said. Although her sons would be demons, they would have the advantage of being killed by the Personality of Godhead Himself. She remembered this incident by the grace of the Lord, and her breasts flowed blood instead of milk. In many instances we find that when a mother is moved by affection for her sons, milk flows from her breasts. In the case of the demon's mother, the blood could not transform into milk, but it flowed down her breasts as it was. Blood transforms into milk. To drink milk is auspicious, but to drink blood is inauspicious, although they are one and the same thing. This formula is applicable in the case of cow's milk also.