Fire, in the spiritual sense, can mean either love or hatred depending on the context, just as natural fire can be either comforting in keeping you warm, or scary in burning down your house. Our language reflects this, too -- we use concepts like a smoldering hatred or a burning love. So fire signifies a love, either a good love of the neighbor and to the Lord, or, in a bad sense, selfish love of oneself that, if unchecked by conscience, leads to hatred of anyone that opposes it.

'Word,' as in Isaiah 9:8, signifies the doctrine of internal and external worship. 'Word,' as in Psalms 119:6-17, stands for doctrine in general.

'The Word,' as in Psalms 147:18, signifies divine good united with divine truth.

The whole Word is nothing but the doctrine of love towards the Lord, and love towards our neighbor, as in Matthew 22.

(References: Arcana Coelestia 1288)