Vishnupurana 5.12.p2

5.12.p2

Having thus inaugurated Krishna, Indra, the husband of Sachi, again affectionately said—"I have done this at the request of the cattle; hear, I shall speak something else to thee, O noble one, being desirous of relieving the earth of her burden. O foremost of men, a portion of mine, under the name of Arjuna, has descended upon earth—do thou protect him always. He shall assist thee in relieving the earth of her burden. He should be protected by thee, O Slayer of Madhu, like thy own Self".