Then He said to them, “These are the words which I spoke to you while I was still with you, that all things must be fulfilled which were written in the Law of Moses and the Prophets and the Psalms concerning Me.” And He opened their understanding, that they might comprehend the Scriptures.
Luke 24:44-45 NKJV
Therefore, since we have such hope, we use great boldness of speech— unlike Moses, who put a veil over his face so that the children of Israel could not look steadily at the end of what was passing away. But their minds were blinded. For until this day the same veil remains unlifted in the reading of the Old Testament, because the veil is taken away in Christ. But even to this day, when Moses is read, a veil lies on their heart. Nevertheless when one turns to the Lord, the veil is taken away. Now the Lord is the Spirit; and where the Spirit of the Lord is, there is liberty. But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as by the Spirit of the Lord.
II Corinthians 3:12-18 NKJV
How do you read and study the Old Testament? Is it the same way the Jewish leaders did by focusing on the morals and examples of the patriarchs? On rules and traditions and yet missing the main point of it which is Jesus Christ. Seeing the Messiah in the Old Testament is the litmus test of our understanding and comprehension of the scriptures. Sadly, most of us neglect this study. As Paul would say focusing on the shadows not the substance.
So let no one judge you in food or in drink, or regarding a festival or a new moon or sabbaths, which are a shadow of things to come, but the substance is of Christ.
Colossians 2:16-17 NKJV
So how can we find Jesus in the Old testament? There are 3 ways to do it. The first one is by looking at PROPHECIES about Him. These passages show tell us about the coming Messiah’s life and reign. There are estimated 300 prophecies about Christ and some of these are clearly fulfilled the first time He came on earth while others will be in the future. These prophecies were made hundreds of years before Jesus walked on the earth.
Then Paul, as his custom was, went in to them, and for three Sabbaths reasoned with them from the Scriptures, explaining and demonstrating that the Christ had to suffer and rise again from the dead, and saying, “This Jesus whom I preach to you is the Christ.”
Acts 17:2-3 NKJV
https://bible.com/bible/114/act.17.2-3.NKJV
For dogs have surrounded Me; The congregation of the wicked has enclosed Me. They pierced My hands and My feet; I can count all My bones. They look and stare at Me. They divide My garments among them, And for My clothing they cast lots.
Psalms 22:16-18 NKJV
This account in Psalm 22 is astonishing if you consider it was written thousand of years before crucifixion was invented. Also it's not just one isolated verse, The whole chapter of Ps 22 is about the crucifixion just like the whole chapter of Isaiah 53 is about the vicarious suffering of Christ.
The second way we can find Jesus in the Old Testament is through the many times He was foreshadowed which is called TYPOLOGY. These are person, places, things and events that picture the future life and deliverance given by the Messiah.
And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up,
John 3:14 NKJV
Then the Lord said to Moses, “Make a fiery serpent, and set it on a pole; and it shall be that everyone who is bitten, when he looks at it, shall live.” So Moses made a bronze serpent, and put it on a pole; and so it was, if a serpent had bitten anyone, when he looked at the bronze serpent, he lived.
Numbers 21:8-9 NKJV
If God is really the author of the Bible, He would then have one main story in mind. All other casts and plots in the Scripture are avenues and Easter eggs to point towards the main story and protagonist which is God Himself saving mankind in spite of our rebellion.
The third and last way we find Jesus is through the manifestation of Himself, interacting with the Old Testament saints. The term theologians use is CHRISTOPHANIES. The Son Himself, stepping in history before the incarnation. If Jesus claimed that Abraham saw Him and before Abraham was, He was already the I AM, the Jehovah God, would you believe Him?
Your father Abraham rejoiced to see My day, and he saw it and was glad.” Then the Jews said to Him, “You are not yet fifty years old, and have You seen Abraham?” Jesus said to them, “Most assuredly, I say to you, before Abraham was, I AM.”
John 8:56-58 NKJV