Then they set out from Mount Hor by the way of the Red Sea, to go around the land of Edom; and the people became impatient because of the journey. The people spoke against God and Moses, Why have you brought us up out of Egypt to die in the wilderness? For there is no food and no water, and we loathe this miserable food. The Lord sent fiery serpents among the people and they bit the people, so that many people of Israel died. So the people came to Moses and said, We have sinned, because we have spoken against the Lord and you; intercede with the Lord, that He may remove the serpents from us. And Moses interceded for the people. Then the Lord said to Moses, make a fiery serpent and set it on a standard; and it shall come about, that everyone who is bitten, when he looks at it, he will live. And Moses made a bronze serpent and set it on the standard; and it came about, that if a serpent bit any man, when he looked to the bronze serpent, he lived.

Numbers 21:4-9

So what can we conclude from this. We know that God made a covenant of healing with the Israelites in Exodus 15:26. We know from Deuteronomy 28:20-22;58-62 if you disobey God’s commands, one of the curses is sickness. We know from what you just read in Numbers 21:4-9, the Israelites did not like the manna God was feeding them and they complained about it, which is disobedience. The Israelites broke the covenant by their complaining and snakes were permitted to bite them. When the Israelites repented and came back in obedience to God, God was able to fulfill His part of the covenant and heal them. God is not a covenant breaker, He may give you a better covenant, but He will never break His covenant because He said My covenant I will not break, nor alter the word which has gone out from my lips. (Psalm 89:34)

Isaiah 53, the redemptive chapter

Surely He has borne our griefs and carried our sorrows; yet we esteemed Him stricken, smitten by God, and afflicted.

Isaiah 53:4

But He was wounded for our transgressions, He was bruised for our iniquities; the chastisement for our peace was upon Him, and by His stripes we are healed.

Isaiah 53:5