Valmiki Ramayana Kishkindha Kanda Sarga 7 Shloka 3
Original Shlokaसत्यं ते प्रतिजानामि त्यज शोकमरिन्दम। करिष्यामि तथा यत्नं यथा प्राप्स्यसि मैथिलीम्4.7.3।।
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अरिन्दम O subduer of enemies, सत्यम् truth, प्रतिजानामि I promise you, शोकम् sorrow, त्यज give up, मैथिलीम् Maithili, यथा as, प्राप्स्यसि will obtain, तथा that way, यत्नम् effort, करिष्यामि I will make
'O subduer of enemies, give up sorrow. I promise I will make necessary effort so that you will obtain the princess from Mithila.