'The altar (on which the sacrifice is supposed to be offered) is that world (heaven), O Gautama; its fuel is the sun itself, the smoke his rays, the light the day, the coals the moon, the sparks the stars.

In plain words: The king begins by comparing heaven to a sacrificial fire. The sun is its fuel and the sun's rays are its smoke. The day is its light, the moon its glowing coals and the stars its sparks.