But on the morrow all the congregation of the children of Israel murmured against Moses and against Aaron, saying, Ye have killed the people of the LORD.

Wesley's Notes

16:41 On the morrow - Prodigious wickedness and madness so soon to forget such a terrible instance of Divine vengeance! The people of the Lord - So they call those wicked wretches, and rebels against God! Tho' they were but newly saved from sharing in the same punishment, and the survivors were as brands plucked out of the burning, yet they fly in the face of Moses and Aaron, to whose intercession they owe their preservation.

Jamieson-Fausset-Brown Bible Commentary

41. the children of Israel murmured against Moses and against Aaron, saying, Ye have killed the people of the Lord-What a strange exhibition of popular prejudice and passion-to blame the leaders for saving the rebels! Yet Moses and Aaron interceded for the people-the high priest perilling his own life in doing good to that perverse race.

Matthew Henry's Concise Commentary

16:41-50 The gaping earth was scarcely closed, before the same sins are again committed, and all these warnings slighted. They called the rebels the people of the Lord; and find fault with Divine justice. The obstinacy of Israel notwithstanding the terrors of God's law, as given on mount Sinai, and the terrors of his judgments, shows how necessary the grace of God is to change men's hearts and lives. Love will do what fear cannot. Moses and Aaron interceded with God for mercy, knowing how great the provocation was. Aaron went, and burned incense between the living and the dead, not to purify the air, but to pacify an offended God. As one tender of the life of every Israelite, Aaron made all possible speed. We must render good for evil. Observe especially, that Aaron was a type of Christ. There is an infection of sin in the world, which only the cross and intercession of Jesus Christ can stay and remove. He enters the defiled and dying camp. He stands between the dead and the living; between the eternal Judge and the souls under condemnation. We must have redemption through His blood, even the remission of sins. We admire the ready devotion of Aaron: shall we not bless and praise the unspeakable grace and love which filled the Saviour's heart, when he placed himself in our stead, and bought us with his life? Greatly indeed hath God commended his love towards us, in that while we were yet sinners, Christ died for us, Ro 5:8.