On the fourth day, the deities
are carried in a Kalpavriksha Vahana in the morning.
Kalpavriksham is a tree that is
believed to grant boons and fulfil devotees wishes.
The vehicle shaped like the Kalpavriksham signifies
that the Lord grants boons and fulfils the wishes of
his devotees.
In the night, after the Unjal Seva,
the deities are carried in a Sarvabhoopala Vahana.
Sarvabhoopala means 'all the kings
of Mother Earth'. According to the Hindu religion, kings,
like Lord Vishnu, should always protect their people
(na vishnuhu prithivi pathihi).
To thank Lord Vishnu for his ideals
and pray to him, the kings take the form of the Sarvabhoopala
Vahana on the fourth day of Brahmotsavam.