Ramayana
तथा शपन्त्यां वैदेह्यां प्रादुरासीत्तदद्भुतम् । भूतलादुत्थितं दिव्यं सिंहासनमनुत्तमम् ॥ 7-97-18 ॥
As Vaidehi was thus taking her oath, that marvel appeared: a divine and most excellent throne rose up from the surface of the earth.
english translation