Rishi Bharadwaj wanted to study all the four Vedas and so he started Vedaadhyana and continued it for many years, when he realized that his life may end, he Prayed for Indra. Indra appeared before him and wanted know his wish. Rishi Bharadwaj asked for one hundred years of more longevity. Indra before granting the wish wanted to know what the Rishi would do with one hundred years of Ayush. The Rishi replied that he would pursue Vedaadhyana. Indra disappeared and Rishi continued with his Vedaadhyana and finally could realize that even extra one hundred years were also coming to an end. So, he prayed for Indra. Indra again appeared and the Rishi again wished for one more hundred years of longevity. Indra again wanted to know what the Rishi would do with one more hundred years of Ayush. The Rishi replied that his Vedaadhyana was incomplete and so would pursue the Vedaadhyana and Indra again granted one more hundred years of Ayush to the Rishi. Like this Rishi Bharadwaj continued Vedaadhyana for three hundred years. But yet the Rishi was not content with Vedaadhyana and was unhappy. Indra appeared before him without praying and enquired why the Rishi was unhappy, even after 300 years of Vedaadhyana. The Rishi informed Indra, he could not complete Vedaadhyana, despite deeply studying them. Then Indra created three great mountains in front of him and enquired whether the Rishi knew anything about them. The Rishi pleaded his ignorance. Then Indra told him that they are the symbolic representation of Knowledge contained in three Vedas. Indra took one fistful of sand from each one of the mountains and explained to the Rishi that after three hundred years of strenuous efforts the Rishi could attain only fistful of knowledge out of great mountains of Knowledge from Vedas.