Srimad Bhagavatam Canto 09, Chapter 06, Text 26

SB 9.6.26

bharya-satena nirvinna
 rsayo ’sya krpalavah
istim sma vartayam cakrur
 aindrim te susamahitah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
Although Yuvanasva went into the forest with his one hundred wives, all of them were very morose. The sages in the forest, however, being very kind to the King, began very carefully and attentively performing an Indra-yajña so that the King might have a son.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
One may enter the vanaprastha order of life with his wife, but the vanaprastha order means complete retirement from household life. Although King Yuvanasva retired from family life, he and his wives were always morose because he had no son.
Srimad Bhagavatam Canto 09, Chapter 06, Text 25
Srimad Bhagavatam Canto 09, Chapter 06, Text 27