ऋषेस्तु वेदशिरसस् तुषिता नाम पत्न्यभूत् ।
तस्यां जज्ञे ततो देवो विभुरित्यभिविश्रुतः ॥ २१ ॥
rseh-of the saintly person; tu-indeed; vedasirasah-Vedasira; tusita-Tusita; nama-named; patni-the wife; abhut-begat; tasyam-in her (womb); jajne-took birth; tatah-thereafter; devah-the Lord; vibhuh-Vibhu; iti-thus; abhivisrutah-celebrated as.
Vedasira was a very celebrated rsi. From the womb of his wife, whose name was Tusita, came the avatara named Vibhu.