'Murmuring' in the Bible

Moses said, "You will know this when the Lord gives you meat to eat in the evening and bread in the morning to satisfy you, because the Lord has heard your murmurings that you are murmuring against him. As for us, what are we? Your murmurings are not against us, but against the Lord."

It stands still, but I cannot recognize its appearance; an image is before my eyes, and I hear a murmuring voice: