17 And when Joshua heard the noise of the people as they shouted, he said unto Moses, There is a noise of war in the camp.

18 And he said, It is not the voice of them that shout for mastery, neither is it the voice of them that cry for being overcome: but the noise of them that sing do I hear.

Back when Moses had ascended the mountain, we were told that his minister, Joshua, accompanied him. So now Joshua met Moses along the way down the mountain, reporting that he had already heard a tumult coming up from the valley down below. Joshua assumed that it was the noise of a battle, Moses, however, heard the notes of a song.

These verses are describing the noises of two types of trouble. In fact, it is the two fundamental types of trouble that are the source of all of our problems, both individually and collectively. There is the trouble of a foreign attack, outside sources seeking our destruction and causing us harm. Then there is the trouble of deliberate disobedience, the idolatry and revelry that we inflict upon ourselves. One sounds like discordant chaos, the other like patterned notes of blasphemy.

No wonder Joshua thought he heard the sounds of the first, for persecution inflicted upon the Israelites had been the pattern for many years. But now the nature of Israel’s trouble was changing. It was shifting from an external enemy to an internal one, and Moses was perceiving that change already.