Valmiki Ramayana Sundara Kanda Sarga 35 Shloka 22
Original Shlokaभ्राता तस्य च द्वैमात्रस्सौमित्रिरपराजितः। अनुरागेण रूपेण गुणैश्चैव तथाविधः।।5.35.22।।
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तस्य his, द्वैमात्रः born of a different mother, भ्राता brother, अपराजितः one who has never been defeated, सौमित्रिः Saumitri, अनुरागेण in affection, रूपेण in charm, गुणैश्चैव in virtues, तथाविधः similar to him.
"His invincible brother Saumitri born of a different mother is a replica of Rama in affection, charm and virtues.