Valmiki Ramayana Ayodhya Kanda Sarga 4 Shloka 33
Original Shlokaश्रुत्वा पुष्येण पुत्रस्य यौवराज्याऽभिषेचनम्। प्राणायामेन पुरुषं ध्यायमाना जनार्दनम्।।2.4.33।।
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पुष्येण In Pushya constellation, पुत्रस्य son's, यौवराज्याभिषेचनम् installation as heirapparent, श्रुत्वा having heard, प्राणायामेन by controlling the breath, पुरुषम् supreme god, जनार्दनम् Lord Visnu, ध्यायमाना meditating upon.
Having heard that installation of her son as heirapparent was planned in Pushya constellation, Kausalya was meditating upon the Supreme Person, Lord Visnu by controlling her breath (Pranayama).