Valmiki Ramayana Yuddha Kanda Sarga 63 Shloka 36
Original Shlokaअद्यरामस्यतद्दृष्टवामयानीतंरणाच्छिरः । सुखीभवमहाबाहो सीताभवतुदुःखिता ।।6.63.36।।
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महाबाहो mighty armed, अद्य now, रणात् from war, आनीतम् will bring, रामस्य Rama's, तत् that, शिरः head, दृष्टवा seeing, सुखी be happy, भव you, सीता Sita, दुःखिता sad, भवतु will be.
"Be happy today, O Mighty armed brother! I will bring Rama's head from the battlefield. Sita will be sad. You will see."