SB 6.1.24
tasya pravayasah putra
dasa tesam tu yo ’vamah
balo narayano namna
pitros ca dayito bhrsam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
That old man Ajamila had ten sons, of whom the youngest was a baby named Narayana. Since Narayana was the youngest of all the sons, he was naturally very dear to both his father and his mother.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The word pravayasah indicates Ajamila’s sinfulness because although he was eighty-eight years old, he had a very young child. According to Vedic culture, one should leave home as soon as he has reached fifty years of age; one should not live at home and go on producing children. Sex life is allowed for twenty-five years, between the ages of twenty-five and forty-five or, at the most, fifty. After that one should give up the habit of sex life and leave home as a vanaprastha and then properly take sannyasa. Ajamila, however, because of his association with a prostitute, lost all brahminical culture and became most sinful, even in his so-called household life.