Originating in historical Vedic religion, 'Pravargya' (Sanskrit प्रवर्ग्य), also known as 'Ashvina-pravaya', is an introductory or preliminary ceremony to the (of which there are several kinds, the five-day Agnishtoma Soma Yagya forming the basic model). In the Pravargya Yagya, an earthen pot is fashioned from clay dug up from the ground, placed on a fire-altar, and used to boil milk which is offered to the Ashvins, the twin Rigvedic gods of Ayurvedic medicine.