Valmiki Ramayana Ayodhya Kanda Sarga 21 Shloka 47
Original Shlokaशोकस्सन्धार्यतां मात र्हृदये साधु मा शुचः। वनवासादिहैष्यामि पुनः कृत्वा पितुर्वचः।।2.21.47।।
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मात O mother, शोकः sorrow, हृदये in the heart, साधु prudently, सन्धार्यताम् be subdued, मा शुचः do not grieve, पितुः father's, वचः words, कृत्वा having fulfilled, वनवासात् from exile, पुनः again, इह here, एष्यामि will come back.
Do not grieve, O mother Be prudent enough to subdue your sorrow in your heart. Having fulfilled father's words, I shall come back from my sojourn in the forest.