21:4. And they marched from mount Hor, by the way that leadeth to the Red Sea, to compass the land of Edom. And the people began to be weary of their journey and labour:
21:5. And speaking against God and Moses, they said: Why didst thou bring us out of Egypt, to die in the wilderness? There is no bread, nor have we any waters: our soul now loatheth this very light food.
Very light food… So they call the heavenly manna: thus worldlings loathe the things of heaven, for which they have no relish.
21:6. Wherefore the Lord sent among the people fiery serpents, which bit them and killed many of them.
Fiery serpents… They are so called, because they that were bitten by them were burnt with a violent heat.
21:7. Upon which they came to Moses, and said; We have sinned, because we have spoken against the Lord and thee: pray that he may take away these serpents from us. And Moses prayed for the people.
21:8. And the Lord said to him: Make a brazen serpent, and set it up for a sign: whosoever being struck shall look on it, shall live.
21:9. Moses therefore made a brazen serpent, and set it up for a sign: which when they that were bitten looked upon, they were healed.
A brazen serpent… This was a figure of Christ crucified, and of the efficacy of a lively faith in him, against the bites of the hellish serpent. John 3.14.
21:10. And the children of Israel setting forwards camped in Oboth.