Moses and Aaron delivered a pointed warning to the Israelites who kept complaining about their food in the wilderness. The manna had been given with a "radiant countenance" because the people had asked for bread out of genuine hunger. But the complaining did not stop. The people kept caviling, kept accusing, kept grumbling against their leaders.
Moses and Aaron's response, recorded in the Mekhilta DeRabbi Yishmael's reading of (Exodus 16:8), was both humble and devastating. They told the people: if your complaints were directed only against us, we could tolerate it. Moses and Aaron were human beings. They could absorb insults, endure criticism, and move on. Human leaders can bear the weight of their people's frustration.
But the complaints were not really aimed at Moses and Aaron. They were aimed at God. "The Lord hears your cavilings, whereby you cavil against Him." Every accusation the Israelites hurled at their visible leaders was actually an accusation against the invisible God who stood behind them. Moses and Aaron were merely the conduit. The real target of Israel's anger was the Living, eternal God Himself.
The phrase "Living, eternal God" is deliberate and chilling. A mortal leader might forget an insult. A mortal leader might die before settling accounts. But the God of Israel is neither mortal nor forgetful. To cavil against Him is to provoke an eternal being who hears every word and remembers every grievance. Moses and Aaron were not threatening the people. They were trying to make them understand the magnitude of what they were doing.