As it has been well stated:
The Old Testament is in the New Testament revealed and the New Testament is in the Old Testament concealed.
But whence comes such a statement?
From Jesus Himself who made statements such as:
You search the Scriptures because you think that in them you have eternal life; it is these that testify about Me (John 5:39).
And He said to them, "O foolish men and slow of heart to believe in all that the prophets have spoken! Was it not necessary for the Christ to suffer these things and to enter into His glory?"
Then beginning with Moses and with all the prophets, He explained to them the things concerning Himself in all the Scriptures (Luke 24:25-27).
In keeping with this concept of symbolism, allegory, metaphor, likenesses, etc. let us consider Exodus 15:22-27 which notes:
Then Moses led Israel from the Red Sea, and they went out into the wilderness of Shur; and they went three days in the wilderness and found no water.
When they came to Marah, they could not drink the waters of Marah, for they were bitter; therefore it was named Marah. So the people grumbled at Moses, saying, "What shall we drink?"
Then he cried out to the LORD, and the LORD showed him a tree; and he threw it into the waters, and the waters became sweet. There He made for them a statute and regulation, and there He tested them. And He said, "If you will give earnest heed to the voice of the LORD your God, and do what is right in His sight, and give ear to His commandments, and keep all His statutes, I will put none of the diseases on you which I have put on the Egyptians; for I, the LORD, am your healer."
Then they came to Elim where there were twelve springs of water and seventy date palms, and they camped there beside the waters.
Well, note some of the key aspects:
1) They traveled for three days without water which means that they were headed for certain death.
2) They are thirsty, have not water to drink and upon finding some water they find it undrinkable as it is bitter—polluted, un-potable.
3) They ask what they are to drink.
4) Moses turns to YHVH for an answer.
5) The waters are healed, as it were, via the employment of a tree (wood, timber, stock, plank, stalk, etc.).
6) The statute and regulation was to not do like the Pagan Gentiles and their false gods but to heed YHVH.
7) They come upon twelve springs of water and seventy date palms (or, palm trees).
Here is some elucidation as to the correlations with Jesus’ life and ministry:
1) For three days they were slowly dying and Jesus was dead for three days and resurrected: came to life again as would they.
2) That which the world has to offer is toxic. It is a mirage of sorts: you thirst, see water and are delighted only to have your thirst be even more exacerbated by the expectation and subsequent letdown.
Truly, truly, I say to you, unless one is born of water and the Spirit he cannot enter into the kingdom of God….
He who believes in Me, as the Scripture said, 'From his innermost being will flow rivers of living water'….
but whoever drinks of the water that I will give him shall never thirst; but the water that I will give him will become in him a well of water springing up to eternal life (John 3:5, 7:38 and 4:14).
3) Reaching a point of desperation is the first step towards repentance; the term “I could not help myself” is quite literal in this case. You are out in the middle of nowhere, along with thousands of people, and are about to die of thirst; you literally cannot help yourself.
4) The people turn to Moses, their earthly leader, and Moses turns to YHVH, the leader of leaders.
5) The tree/wood via which the waters are healed is a clear symbol of Jesus upon the cross as via His work on the cross, we are healed “by His scourging we are healed” (Isaiah 53:5):
Christ redeemed us from the curse of the Law, having become a curse for us—for it is written, "Cursed is everyone who hangs on a tree" (Galatians 3:13 quoting Deuteronomy 21:23).
6) The statute and regulation was to not do like the Pagan Gentiles and their false gods but to heed YHVH. The people turn to Moses, Moses turns to YHVH and now the people are taught to turn to YHVH and not turn away.
7) The twelve springs of water appear to represent the twelve tribes of Israel, at least immediately, but also the twelve apostles. The seventy date palms/palm trees appear to represent the first seventy disciples of Jesus:
…the Lord appointed seventy others, and sent them in pairs ahead of Him to every city and place where He Himself was going to come (Luke 10:1).
It may be of interest to note that some manuscripts have the number at seventy two. However, a list of the 70 disciples of Jesus was compiled by Hippolytus circa 220 AD. Slot number 42 reads, “Olympus and Rhodion were martyred in Rome” to which Ken Johnson comments, “The Scripture indicated James was an unbeliever until after the Resurrection. Since number 42 contains two people, we can conclude that James was not one of the original seventy” (see my review of the book in which this statement is made here; it was from Ancient Church Fathers, p. 11)
Thus, we see how a story about being thirsty for three days, tree/wood, water and trees teaches important lessons about Jesus; even centuries before His incarnation.