1 And when king Arad the Canaanite, which dwelt in the south, heard tell that Israel came by the way of the spies; then he fought against Israel, and took some of them prisoners. 2 And Israel vowed a vow unto the LORD, and said, If thou wilt indeed deliver this people into my hand, then I will utterly destroy their cities. 3 And the LORD hearkened to the voice of Israel, and delivered up the Canaanites; and they utterly destroyed them and their cities: and he called the name of the place Hormah. 4 And they journeyed from mount Hor by the way of the Red sea, to compass the land of Edom: and the soul of the people was much discouraged because of the way. 5 And the people spake against God, and against Moses, Wherefore have ye brought us up out of Egypt to die in the wilderness? for there is no bread, neither is there any water; and our soul loatheth this light bread. 6 And the LORD sent fiery serpents among the people, and they bit the people; and much people of Israel died. 7 Therefore the people came to Moses, and said, We have sinned, for we have spoken against the LORD, and against thee; pray unto the LORD, that he take away the serpents from us. And Moses prayed for the people. 8 And the LORD said unto Moses, Make thee a fiery serpent, and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live. 9 And Moses made a serpent of brass, and put it upon a pole, and it came to pass, that if a serpent had bitten any man, when he beheld the serpent of brass, he lived. 10 And the children of Israel set forward, and pitched in Oboth. 11 And they journeyed from Oboth, and pitched at Ije-abarim, in the wilderness which is before Moab, toward the sunrising. 12 From thence they removed, and pitched in the valley of Zared. 13 From thence they removed, and pitched on the other side of Arnon, which is in the wilderness that cometh out of the coasts of the Amorites: for Arnon is the border of Moab, between Moab and the Amorites. 14 Wherefore it is said in the book of the wars of the LORD, What he did in the Red sea, and in the brooks of Arnon, 15 And at the stream of the brooks that goeth down to the dwelling of Ar, and lieth upon the border of Moab. 16 And from thence they went to Beer: that is the well whereof the LORD spake unto Moses, Gather the people together, and I will give them water. 17 Then Israel sang this song, Spring up, O well; sing ye unto it: 18 The princes digged the well, the nobles of the people digged it, by the direction of the lawgiver, with their staves. And from the wilderness they went to Mattanah: 19 And from Mattanah to Nahaliel: and from Nahaliel to Bamoth: 20 And from Bamoth in the valley, that is in the country of Moab, to the top of Pisgah, which looketh toward Jeshimon. 21 And Israel sent messengers unto Sihon king of the Amorites, saying, 22 Let me pass through thy land: we will not turn into the fields, or into the vineyards; we will not drink of the waters of the well: but we will go along by the king's high way, until we be past thy borders. 23 And Sihon would not suffer Israel to pass through his border: but Sihon gathered all his people together, and went out against Israel into the wilderness: and he came to Jahaz, and fought against Israel. 24 And Israel smote him with the edge of the sword, and possessed his land from Arnon unto Jabbok, even unto the children of Ammon: for the border of the children of Ammon was strong. 25 And Israel took all these cities: and Israel dwelt in all the cities of the Amorites, in Heshbon, and in all the villages thereof. 26 For Heshbon was the city of Sihon the king of the Amorites, who had fought against the former king of Moab, and taken all his land out of his hand, even unto Arnon. 27 Wherefore they that speak in proverbs say, Come into Heshbon, let the city of Sihon be built and prepared: 28 For there is a fire gone out of Heshbon, a flame from the city of Sihon: it hath consumed Ar of Moab, and the lords of the high places of Arnon. 29 Woe to thee, Moab! thou art undone, O people of Chemosh: he hath given his sons that escaped, and his daughters, into captivity unto Sihon king of the Amorites. 30 We have shot at them; Heshbon is perished even unto Dibon, and we have laid them waste even unto Nophah, which reacheth unto Medeba. 31 Thus Israel dwelt in the land of the Amorites. 32 And Moses sent to spy out Jaazer, and they took the villages thereof, and drove out the Amorites that were there. 33 And they turned and went up by the way of Bashan: and Og the king of Bashan went out against them, he, and all his people, to the battle at Edrei. 34 And the LORD said unto Moses, Fear him not: for I have delivered him into thy hand, and all his people, and his land; and thou shalt do to him as thou didst unto Sihon king of the Amorites, which dwelt at Heshbon. 35 So they smote him, and his sons, and all his people, until there was none left him alive: and they possessed his land.
[AD 1781] Richard Challoner on Numbers 21:3
Anathema: That is, a thing devoted to utter destruction.
[AD 397] Ambrose of Milan on Numbers 21:4-9
Many things were done in figure which were done in former times. For when he said that the fathers who were bitten by serpents in the desert could not be healed in any other way except that Moses hung up a brazen serpent, and when this was seen, those deadly bites and injurious effects of the poison were cured, he added: But these things were done in figure to instruct us (1 Corinthians 10:6). In the image, a bronze serpent was placed on a cross; because the true one to be crucified was announced to the human race, who would empty the venom of the devilish serpent, cursed in its image, but in truth, would erase all curses of the world.

[AD 1781] Richard Challoner on Numbers 21:5
Very light food: So they call the heavenly manna: thus worldlings loathe the things of heaven, for which they have no relish.
[AD 735] Bede on Numbers 21:6
The wounds caused by the fiery serpent are the poisonous enticements of the vices, which afflict the soul and bring about its spiritual death. The people were murmuring against the Lord. They were stricken by the serpents’ bites. This provides an excellent instance of how one may recognize from the results of an external scourge what a great calamity a person might suffer inwardly by murmuring. In the raising up of the bronze serpent (when those who were stricken beheld it, they were cured) is prefigured our Redeemer’s suffering on the cross, for only by faith in him is the kingdom of death and sin overcome. The sins which drag down soul and body to destruction at the same time are appropriately represented by the serpents, not only because they were fiery and poisonous [and] artful at bringing about death but also because our first parents were led into sin by a serpent, and from being immortal they became mortal by sinning. The Lord is aptly made known by the bronze serpent, since he came in the likeness of sinful flesh. Just as the bronze serpent had the likeness of a fiery serpent but had absolutely none of the strength of harmful poison in its members—rather by being lifted up it cured those who had been stricken by the [live] serpents—so the Redeemer of the human race did not merely clothe himself in sinful flesh but entered bodily into the likeness of sinful flesh, in order that by suffering death on the cross in [this likeness] he might free those who believed in him from all sin and even from death itself.

[AD 1781] Richard Challoner on Numbers 21:6
Fiery serpents: They are so called, because they that were bitten by them were burnt with a violent heat.
[AD 165] Justin Martyr on Numbers 21:9
Tell me, did not God, through Moses, forbid the making of an image or likeness of anything in the heavens or on earth? Yet didn’t he himself have Moses construct the brazen serpent in the desert? Moses set it up as a sign by which those who had been bitten by the serpents were healed. In doing so, was Moses not free of any sin? By this, as I stated above, God through Moses announced a mystery by which he proclaimed that he would break the power of the serpent, who prompted the sin of Adam. He promises that he would deliver from the bites of the serpent (that is, evil actions, idolatries and other sins) all those who believe in him who was to be put to death by this sign, namely, the cross.

[AD 373] Ephrem the Syrian on Numbers 21:9
The serpent struck Adam in paradise and killed him. [It also struck] Israel in the camp and annihilated them. “Just as Moses lifted up the serpent in the desert, the Son of Man will be lifted up.” Just as those who looked with bodily eyes at the sign which Moses fastened on the cross lived bodily, so too those who look with spiritual eyes at the body of the Messiah nailed and suspended on the cross and believe in him will live [spiritually]. Thus it was revealed through this brazen [serpent], which by nature cannot suffer, that he who was to suffer on the cross is one who by nature cannot die.

[AD 390] Gregory of Nazianzus on Numbers 21:9
That brazen serpent was hung up as a remedy for the biting serpents, not as a type of him that suffered for us but as a contrast. It saved those that looked upon it, not because they believed it to live but because it was killed, and killed with it were the powers that were subject to it, being destroyed as it deserved. And what is the fitting epitaph for it from us? “O death, where is your sting? O grave, where is your victory?” You are overthrown by the cross. You are slain by him who is the giver of life. You are without breath, dead, without motion, even though you keep the form of a serpent lifted up high on a pole.

[AD 430] Augustine of Hippo on Numbers 21:9
To be made whole of a serpent is a great sacrament. What is it to be made whole of a serpent by looking upon a serpent? It is to be made whole of death by believing in one dead. And nevertheless Moses feared and fled. What is it that Moses fled from that serpent? What, brethren, save that which we know to have been done in the gospel? Christ died, and the disciples feared and withdrew from that hope wherein they had been.

[AD 1781] Richard Challoner on Numbers 21:9
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.
[AD 1781] Richard Challoner on Numbers 21:14
The book of the wars: An ancient book, which, like several others quoted in scripture, has been lost.