Commentaries:
The people thought that they were complaining against Moses and Aaron, but Moses said, "No, you are murmuring against God." They did not see God in the same way that Moses did. He saw God ruling over His creation. He understood that he was God's servant, so when they complained against Moses, they were really complaining against God. Moses interpreted the situation as, if God wanted something done differently, He probably would have moved Moses to act differently.
John W. Ritenbaugh
Submitting (Part 2)