From Hindupedia, the Hindu Encyclopedia
By Swami Harshananda
Vaiśvadeva literally means ‘pertaining to all the gods’.
This is the first of the four Vedic sacrifices listed under Cāturmāsya. It is performed mainly to attain heaven. It is spread over two days. On the first day an oblation with the pañcahotṛ formula and a cake are offered to the Vaiśvānara Agni.
A new fire is generated on the second day mixed with the existing āhavanīya fire. This is followed by several steps of the sacrifice which are too complicated to mention. The left-over offering of Vājina has to be consumed by the sacrificer.
- The Concise Encyclopedia of Hinduism, Swami Harshananda, Ram Krishna Math, Bangalore