Mahabharata Udyoga Parva Chapter 98:2

Mahabharata Udyoga Parva (Bhagwat Yana Parva) Chapter 98:2 These blazing weapons also of every kind that thou seest, belonged, O Matali, to the Daityas who have been deprived of their sovereignty. These weapons are incapable of deterioration, and when hurled at the foe always return into the hand that hurleth them. Obtained by the gods as the booty of war, they require considerable mental energy to be used against foes. Here dwelt in days of yore many tribes of Rakshasas and Daityas, possessed of many kinds of celestial weapons, but they were all vanquished by the gods. Behold, there, in Varuna's lake is that fire of blazing flames, and that discus of Vishnu surrounded by the lustrous splendour of mighty caloric. Behold, there lieth that knotty bow that was created for the destruction of the world. It is always protected with great vigilance by the gods, and it is from this bow that the one wielded by Arjuna hath taken its name. Endued with the strength of a hundred thousand bows, the power it assumes at the hour of battle is indescribably great. It punishes all punishable wicked kings endued with the nature of Rakshasas. This fierce weapon was first created by Brahman, the utterer of the Vedas. The great preceptor Sukra hath said that this weapon is a terrible one in respect of all kings. Endued with great energy, it is held by the sons of the Lord of waters. Behold, there in the umbrella-room is the umbrella of the Lord of the waters. It droppeth refreshing showers like the clouds. The water dropped from this umbrella, though pure as the moon, is yet enveloped by such darkness that it cannot be seen by anybody. There, in these regions, O Matali, innumerable are the wonders to be seen. Your business, however, will suffer if we spend more time here. We will, therefore, leave this region soon.