In plain words
Dhruva believed the words of Nārada, the mind-born son of Brahmā, fully and with his whole heart. That very faith came there in visible form. But the boy did not know the ways of the world. Viṣṇu came and asked, 'My child! What do you want?' And the boy Dhruva: You, who know where I am and how I am, have come to the very place where I sit in this dense forest. You know where I am contemplating. Do You not know what I want? God was not so lacking in wit. God is more learned than all of us. My child! I know where you are. I know what your wish is, but I have a way of Mine. Thought, word, action: the three must become one. Only then am I ready to fulfil your wish. At home you said you would pray to God and ask for the boon to sit on your father's lap. You did tapas as you said. You did tapas as you thought. I must test whether there are words to match that resolve and that tapas! Dhruva said: I came searching for a piece of glass, in this vāsanā for the things of the world. My wish to sit on my father's lap is a worthless piece of glass. But Your darśan appears to me as a ruby. How fortunate it is for me, who came for a piece of glass, to find so great a ruby. He said he no longer needed the piece of glass. There God caught him neatly. My child! Resolving and doing have become one, but in asking you ask for another thing. Of these three, two have come together as one. One has gone apart. The two make the majority. So He sent him back, telling him to rule the kingdom again. For every feeling God looks for purity of thought, word and deed. Thoughts, words, action must become one. To ask for one thing while the doing is another is not right. With so great a resolve and after so much tapas, though Nārāyaṇa Himself appeared before him at the very end, he could not gain it. What was the reason? Precisely a fault of speech.
So you must use speech in a very sacred way. Speech is the child of the mind. The mind has been soiled by resolves and doubts. The mother's very feelings passed to the child. By rights, the mind should come to the feeling of Brahman. It has not. When the father is one kind, the son may be another. The relation is father and son. Prahlāda was a great devotee. Hiraṇyakaśipu was a great villain. From the womb of such a villain was born a son like a fine ruby. Prahlāda was dear to Nārāyaṇa.