From Hindupedia, the Hindu Encyclopedia
By Swami Harshananda
Among the Vedic sacrifices, those that use the soma juice for offering as oblations are called Somayāgas. Out of the seven Somayāgas, the Soḍaśin is the fourth. It is performed to attain vigor. While extracting the soma juice from the cuttings of the plant, sixteen śastras and sixteen stotras are used. Hence it is named as Soḍaśin.
This is done during the third extraction in the evening. A quadrangular cup made of khadira wood is used to keep the soma juice. Indra is the chief deity appeased through this sacrifice.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore