A copper vessel given to Yudhishtira by Surya, as per Mahabharata Vanaparva Chapter 3. Duryodhana had sent the Pandavas to the lac house to get them killed. They escaped into the forests after crossing the Ganga. After killing rakshasas like Hidimba and Baka, the Pandavas reached the kingdom of Panchala and married Krishnaa (Draupadi). The Pandavas returned to Indraprastha but were cheated out of their kingdom by Duryodhana, and had to go into exile for 12 years. They had no way to feed the thousand of Brahmins who accompanied them. Yudhishtira prayed to Surya, who gave him a copper vessel, and said that the vessel would keep getting replenished with food until Draupadi ate her meal everyday.