Valmiki Ramayana Bala Kanda Sarga 14 Shloka 27
Original Shlokaसचित्यो राजसिंहस्य सञ्चित: कुशलैर्द्विजै:। गरुडो रुक्मपक्षो वै त्रिगुणोऽष्टादशात्मक:।।1.14.27।।
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कुशलै: by the skilled, द्विजै: brahmins, रुक्मपक्ष: golden winged, त्रिगुण: thrice, अष्टादशात्मक: eighteen in number, गरुड: like eagle, राजसिंहस्य of Dasaratha who was lion among kings, सचित्य: sacrificial altar, सञ्चित: was erected.
That sacrificial altar of the lion among kings, (Dasaratha), erected by welltrained brahmins was in the shape of the golden winged 'Garuda' it had three ranges and thrice as many fireplaces i.e eighteen in number.