Charles Spurgeon Commentary 1 Kings 20:23

"And the servants of the king of Syria said unto him, Their god is a god of the hills; therefore they were stronger than we: but let us fight against them in the plain, and surely we shall be stronger than they." — 1 Kings 20:23 (ASV)

It was a current heathenish idea that there was one god for a mountain, another for a stream, another for a plain; and these men imagined that the glorious Jehovah was a local deity like their own images were supposed to be.