Valmiki Ramayana Yuddha Kanda Sarga 32 Shloka 11
Original Shlokaसाश्वश्रूर्ममकौसल्यात्वयापुत्रेणराघव: । वत्सेनेवयथाधेनुर्विवत्सावत्सलाकृता ।।6.32.11।।
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राघव Raghava, मम my, श्वश्रूः motherinlaw, कौसल्या Kausalya, वत्सला dear धेनुःयथा like a cow, पुत्रेण about son, त्वया likewise, वत्सेने about her dear son, विवत्साकृता is separated.
"O Raghava! Even my motherinlaw Kausalya is separated from her dear son just as cow is separated from calf."