Following the instructions of the great sage Aurva, Sagara Mahārāja performed aśvamedha sacrifices and thus satisfied the Supreme Lord, who is the supreme controller, the Supersoul of all learned scholars, and the knower of all Vedic knowledge, the Supreme Personality of Godhead. But Indra, the King of heaven, stole the horse meant to be offered at the sacrifice.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
अनन्तर्वाससः कांश्चिदबहिर्वाससोऽपरान् । सोऽश्वमेधैरयजत सर्ववेदसुरात्मकम्
anantarvāsasaḥ kāṃścidabahirvāsaso'parān | so'śvamedhairayajata sarvavedasurātmakam
SB 9.8.7