Valmiki Ramayana Bala Kanda Sarga 46 Shloka 3
Original Shlokaसाऽहं तपश्चरिष्यामि गर्भं मे दातुमर्हसि। ईश्वरं शक्रहन्तारं त्वमनुज्ञातुमर्हसि।।1.46.3।।
1 source checked for this shloka
सा अहम् I, तप: austerities, चरिष्यामि I shall practise, त्वम् you, ईश्वरम् a supreme ruler of the world, शुक्रहंतारम् capable of slaying Indra, गर्भम् embryo (son), मे to me, दातुम् to give, अर्हसि behoves of you, अनुज्ञातुम् to give consent, अर्हसि behoves.
I shall practise austerities. You ought to grant me a son who would be the supreme ruler of the world and capable of killing Indra. You can say yes (if you will)".