Valmiki Ramayana Yuddha Kanda Sarga 18 Shloka 10
Original Shlokaअमित्रास्तत्कुलीनाश्चप्रातिदेश्याश्चकीर्तिताः । व्यसनेषुप्रहर्तारस्तस्मादयमिहागतः ।।6.18.10।।
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तत्कुलीनाश्च: of kings of same clan, प्रातिदेश्याश्च: kings of adjoining countries, अमित्रा: not friendly ones, व्यसनेषु: when in difficulties, प्रहर्तारः keep attacking, कीर्तिताः renowned, तस्मात् on account of this, अयम् he has, इह: here, आगतः come.
"When in difficulty kings of the same clan of adjoining countries keep attacking the renowned and so they are declared as enemies. It is on account of this cause he (Vibheeshana) has come here."