When Lord Vamana Deva asked for 3 paces of land, He did not do so without a prelude! First He praised all the brahmans who were guiding Bali on his Yagnas. Then he praised Bali’s ancestors HiranyaKasipu and Hiranyaksa who were actually Asuras killed by the Lord himself! Finally he showered praises on Prahalad who was Bali’s grandfather. After hearing all the praises, Bali got ready to grant Vamana his wish. But Sukacarya stopped him and explained to him that the person who had come was none other than Lord Vishnu himself and that He had come at Indra’s behest to destroy all that Bali had rightfully earned.
But Bali was steadfast in his dharma that he had to fulfil his promise. Sukacarya tried his best to stop him by taking the form of a bee and hiding in the spout of the water jug so that water would not flow. But Lord Hari knew about it and poked him with a stick which resulted in the asura guru losing an eye. Bali insisted by saying that if Lord Vishnu himself was seeking alms from him, He would give what the lord wanted because there was no greater glory for him. He added that just because he knew the true form of the brahman, he will not retract from his promise, as that would mean that the king had cheated a brahman which was against the dharma of a king. Therefore he decided that he would carry out his promise irrespective of whether the Lord killed him or showered all his benedictions on him.
The Lord always knew that Bali would fulfil his promise. He also knew what he would do with Bali, since he had promised Prahalada that he would not kill anyone from his family or any of his descendants. All that was left now was to execute his pre-conceived plan.
Now it was time for Lord Hari to pace the land with his steps.
He did it and How!