Explanation:

A fire temple in Zoroastrianism is the place of worship for Zoroastrians, often called dar-e mehr  or agiyari . In the Zoroastrian religion, fire , together with clean water , are agents of ritual purity. Clean, white "ash for the purification ceremonies [is] regarded as the basis of ritual life", which "are essentially the rites proper to the tending of a domestic fire, for the temple [fire] is that of the hearth fire raised to a new solemnity".For, one "who sacrifices unto fire with fuel in his hand ..., is given happiness"