Lord Vāmana appeared before Bali Mahārāja. That was also another cheating. Bali Mahārāja conquered all the universal planets, and the demigods were too much disturbed. So Vāmana Mahārāja . . . Vāmanadeva went to Bali Mahārāja that "You give me some alms. I am brahmin. I have come to beg from you."
So Bali Mahārāja said: "Yes. I'll give You." So He wanted three feet land only. So by one feet the whole universe was covered, upside, and the another feet the other half was covered. Then the third feet Bali Mahārāja said: "Yes, now there is no place. Please keep Your feet on my head. Still my head is there."
So Vāmanadeva was very much pleased by the sacrifice of Bali Mahārāja. He gave up everything for the Lord. So he is one of the great authorities. Out of the twelve authorities, Bali Mahārāja is one of the authorities because he sacrificed everything to satisfy the Lord.