Srimad-Bhagavatam: Canto 4 - Chapter 1 - Verse 12
बालोऽसि बत नात्मानमन्यस्त्रीगर्भसम्भृतम् ।नूनं वेद भवान् यस्य दुर्लभेऽर्थे मनोरथ: ॥ १२ ॥
bālo ’si bata nātmānamanya-strī-garbha-sambhṛtamnūnaṁ veda bhavān yasyadurlabhe ’rthe manorathaḥ
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.
The small child, Dhruva Mahārāja, 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.