Srimad Bhagavatam Canto 06, Chapter 14, Text 26

SB 6.14.26

tatah pahi maha-bhaga
 purvaih saha gatam tamah
yatha tarema dusparam
 prajaya tad vidhehi nah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Therefore, O great sage, please save me and my forefathers, who are descending to the darkness of hell because I have no progeny. Kindly do something so that I may have a son to deliver us from hellish conditions.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
According to Vedic civilization, one gets married simply to have a son, who is needed to offer oblations to his forefathers. King Citraketu responsibly desired to beget a child so that he and his forefathers might be delivered from the darkest regions. He was concerned with how to get pinda, oblations, in the next life, not only for himself but also for his forefathers. Therefore he requested Angira Rsi to favor him by doing something that could help him get a son.
Srimad Bhagavatam Canto 06, Chapter 14, Text 25
Srimad Bhagavatam Canto 06, Chapter 14, Text 27