Valmiki Ramayana Ayodhya Kanda Sarga 90 Shloka 5
Original Shlokaसमागम्य वसिष्ठेन भरतेनाभिवादितः। अबुद्ध्यत महातेजास्सुतं दशरथस्य तम्।।2.90.5।।
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महातेजाः radiant Bharadwaja, वसिष्ठेन with Vasistha, समागम्य having met, भरतेन by Bharata, अभिवादितः greeted, तम् him, दशरथस्य Dasaratha's, सुतम् as son, अबुद्ध्यत knew of.
After meeting Vasistha and greeted by Bharata, the radiant Bharadwaja could recognize he was the son of Dasaratha.