Mbh 13.83.1b

In the midst of that assembly, Indra, saluting the Lord of all the deities and bowing his head unto him with reverence, asked him, saying, 'I desire, O Grandsire, to know why the region of kine is higher, O holy one, than the region of the deities themselves who are the lords of all the worlds. What austerities, what Brahmacharya, O lord, did kine perform in consequence of which they are able to reside happily in a region that is even above that of the deities?' Thus addressed by Indra, Brahman said unto the slayer of Vala, 'Thou hast always, O slayer of Vala, disregarded kine. Hence, thou art not acquainted with the glorious pre-eminence of kine. Listen now to me, O puissant one, as I explain to thee the high energy and glorious pre-eminence of kine, O chief of the celestials! Kine have been said to be the limbs of sacrifice. They represent sacrifice itself, O Vasava! Without them, there can be no sacrifice. With their milk and the Havi produced therefrom, they uphold all creatures. Their male calves are engaged in assisting at tillage and thereby produce diverse kinds of paddy and other seeds. From them flow sacrifices and Havya and Kavya, and milk and curds and ghee. Hence, O chief of the deities, kine are sacred. Afflicted by hunger and thirst, they bear diverse burdens. Kine support the Munis. They uphold all creatures by diverse acts. O Vasava, kine are guileless in their behaviour. In consequence of such behaviour and of many well-performed acts, they are enabled to live always in regions that are even above ours. I have thus explained to thee today, O thou of a hundred sacrifices, the reason, O Sakra of kine residing in a place that is high above that of the deities. Kine obtained many excellent forms, O Vasava, and are themselves givers of boons (to others). They are called Surabhis. Of sacred deeds and endued with many auspicious indications, they are highly sanctifying.