One of the earliest historical references to the god is in the biography of a diplomat from the Saya kingdom, about
Around
The death of a god was seen as a ritualistic sacrifice, and carries heavy symbolic meaning. Similar metaphors can be found in other mythologies: The bodies of dead gods creating the world, with blood turning into rivers, bones turning into mountains, hair turning into forests, and so on. With the emergence of the Eternal Freeze, the world of the gods gradually began to weaken. Until eventually, the house built from Jarilo's corpse could no longer support human life and collapsed, just like it did in the myth.
It is clear the myth's ending was influenced by the Eternal Freeze and the new religions. Before the Eternal Freeze, Jarilo was the typical "birth-death-rebirth" god of nature, whose mythological cycle was the same as that of crops in the northern region of Nycatha, from sowing to growing to harvesting (viewed as crop destruction). However, after the Eternal Freeze, the seasonal cycle was broken, replaced by Belobog's unique climate. In the myth, this climate change is explained by the household affairs between the gods.
It's worth mentioning that in the story, Jarilo goes on a journey from an unfaithful bum to a loyal husband. By the end of the story, he sought redemption from Perun, paying a heavy price for his indiscretions. The changes in Jarilo here were thought to be related to the changing lunar phases, a projection of human understanding on natural phenomena. This understanding continued to hold after the Eternal Freeze emerged and people could no longer observe the moon's phase changes. There was a lack of understanding of such astronomical phenomena, so people were more inclined to draw a moral conclusion to the story — this god's endless cycle of birth-death-rebirth was the price to pay for his love.