Mahabharata 1.3.105

1.3.105

sa evamukto bāḍhamityuktvā tadā tadṛṣabhasya purīṣaṃ mūtraṃ ca bhakṣayitvottaṅkaḥ pratasthe yatra sa kṣatriyaḥ pauṣyaḥ || 105 ||

"Utanka thus commanded, took his departure. And as he was passing along the road he saw a bull of extraordinary size and a man of uncommon stature mounted thereon. And that man addressed Utanka and said, 'Eat thou of the dung of this bull.' Utanka, however, was unwilling to comply. The man said again, 'O Utanka, eat of it without scrutiny. Thy master ate of it before.' And Utanka signified his assent and ate of the dung and drank of the urine of that bull, and rose respectfully, and washing his hands and mouth went to where King Paushya was.