Why the sun is hotter than the moon

I said to Abu Ja’far (asws), ‘May I be sacrificed for you (asws). Which is that thing which makes the sun to be hotter than the moon?’ So he (asws) said: ‘Allah (azwj) Created the sun from the light of the fire and clearness of the water, a layer from this and a layer from this until there were seven layers, then clothed it with a clothing from the fire. Then it became hotter than the moon’. I said, ‘May I be sacrificed for you, and the moon?’ He (asws) said: ‘Allah (azwj) Created the moon from the illumination of the light of the fire and clearness of the water, a layer from this and a layer from this until there were seven layers, then clothed it in a clothing of water, so the moon became colder than the sun’.