यदि यातिदितेर्गर्भं रावणस्सह सीतया | तत्राप्येनं हनिष्यामि न चेद्दास्यति मैथिलीम् || ४-१-११८
Even if Ravana enters into the womb of Diti (mother of demons) along with Sita, I will slay him there if he does not return the daughter of Mithila. [4-1-118]