Svarog is named in a single source, the Primary Chronicle's 1114 entry (following the Slavonic Malalas), where he is presented as the Slavic equivalent of Hephaestus and where tongs are said to have fallen from heaven in his reign so that men learned to forge weapons; the same passage makes Dazhbog his son. His name is bound up with fire, but the older reading of him as a sky-father rests on an etymology that modern linguistics rejects. Some scholars argue he was extrapolated from Svarozhits, the fire god of the Baltic Slavs, and never existed as an independent cult.
Modern Practice
Svarog is called at the forge and at the fire: the first piece of a new work, the first fire of a new workshop, iron and beer. The practice is craft offered to craft - the maker's attention as the offering - and the tongs and hammer are his signs rather than any image.