Srimad Bhagavatam Canto 04, Chapter 08, Text 12

SB 4.8.12

balo ’si bata natmanam
anya-stri-garbha-sambhrtam
nunam veda bhavan yasya
durlabhe ’rthe manorathah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
My dear child, you are unaware that you were born not of my womb but of another woman. Therefore you should know that your attempt is doomed to failure. You are trying to fulfill a desire which is impossible to fulfill.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
The small child, Dhruva Maharaja, was naturally affectionate toward his father, and he did not know that there was a distinction between his two mothers. This distinction was pointed out by Queen Suruci, who informed him that since he was a child he did not understand the distinction between the two queens. This is another statement of Queen Suruci’s pride.
Srimad Bhagavatam Canto 04, Chapter 08, Text 11
Srimad Bhagavatam Canto 04, Chapter 08, Text 13