Valmiki Ramayana Bala Kanda Sarga 16 Shloka 9
Original Shlokaस चाप्यपुत्रो नृपतिस्तस्मिन्काले महाद्युति:। अयजत्पुत्रियामिष्टिं पुत्रेप्सुररिसूदन:।।1.16.9।।
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तस्मिन् काले at that time, महाद्युति: effulgent, अरिसूदन: destroyer of enemies, स:नृपति: that king, अपुत्र: without sons, पुत्रेप्सु: wishing to beget sons, पुत्रियाम् इष्टिम् a sacrifice to obtain sons, अयजत् performed.
At that time, the brilliant king (Dasaratha), destroyer of enemies, who had no sons was performing a sacrifice for sons.