Where did Moses write about Jesus?

As many have already stated, there are many times when Moses spoke of Jesus whether in writing Genesis or though times and situations in his own life... however I'm pretty sure that in the Gospel passage you quoted from Jesus was referring to Deuteronomy 18:15-19 specifically.

15 The Lord thy God will raise up unto thee a Prophet from the midst of thee, of thy brethren, like unto me; unto him ye shall hearken;

16 According to all that thou desiredst of the Lord thy God in Horeb in the day of the assembly, saying, Let me not hear again the voice of the Lord my God, neither let me see this great fire any more, that I die not.

17 And the Lord said unto me, They have well spoken that which they have spoken.

18 I will raise them up a Prophet from among their brethren, like unto thee, and will put my words in his mouth; and he shall speak unto them all that I shall command him.

Ex 34 v 19 The LORD answered: I will make all my goodness pass before you, and I will proclaim my name, “LORD,” before you; I who show favor to whom I will, I who grant mercy to whom I will. ...Jesus is the Goodness of the Father shown to Moses in the entire journey.

All of the feasts are an introduction to the coming and second coming of Christ. The law and the feasts were only the foreshadowing of the coming of the Messiah. The death angel passes by those who have the blood of the lamb on the doorpost, the high priest on the day of atonement was the connection between God and man, etc.
Most don't study the feasts anymore, do you realize that the sacrifice of the blood on the day of atonement was for the forgiveness of sins for the coming year? Jesus's blood covered the sins of the world forever.

Clearly the context of Deut. 18:15-18 is speaking of Jesus Christ because Peter quotes it himself in the context of Jesus.

"For Moses truly said unto the fathers, A prophet shall the Lord your God raise up unto you of your brethren, like unto me; him shall ye hear in all things whatsoever he shall say unto you." Acts 3:22.

Something I do wonder about though is the three distinct persons of the questioning Pharisees in John 1:22-26. They ask John the baptist if he is;

1. The Christ,
2. Elijah,
3. The prophet.

So, Who is "the prophet" if distinct from Christ or Elijah? Is this showing their utter ignorance of the OT law that they should have known as being "teachers of the law?" or is their another prophet?

Jesus a perfect sacrifice (a fulfillment of the law of Moses)

1. the Lamb in the first passover of Exodus 12 had to be kept for four days before the passover for inspection. Jesus fulfulled the law in that way because in the few days leading up to his death, on the passover, he was questioned the most severely by the Jews.(Luke 20:40 - And after that they dared not ask him any question at all)

2. The High Priest and the Jewish leaders went out to seek people who would bring false accusations against Jesus, but they could not find any two people who could agree:--by the testimony off two or more witnesses, a word will be established. (Matthew 26:59-61The chief priests and the whole Sanhedrin were looking for false evidence against Jesus so that they could put him to death. But they did not find any, though many false witnesses came forward).

3. Pilate could not find any fault in Jesus and washed his hands so that his blood would not be on him. (Luke 23:22 And he said to them the third time, "Why, what evil has this man done? ... I have not found any fault in him that deserves death).

You are referring to John 5:46-47 46 For if you believed Moses, you would believe Me; for he wrote about Me. 47 But if you do not believe his writings, how will you believe My words?”

There are several messianic prophecies that were known to the pharisees and specifically Isaiah 7:14, which states that the messiah will be called Immanuel or "God with us".

Isaiah 7:14 14 Therefore the Lord Himself will give you a sign: Behold, the virgin shall conceive and bear a Son, and shall call His name Immanuel.

The pharisees didn't believe Jesus was himself God in the flesh. Using Isaiah 7:14 and the miracles they saw, they should have known and believed Him when he said he was the Son of God and the great "I AM"

Luke 22:70 Then they all said, “Are You then the Son of God?” So He said to them, “You rightly say that I am.”

John 8:58 Jesus said to them, “Most assuredly, I say to you, before Abraham was, I AM.”

Here are some of the verses He was talking about:

Genesis 3:8 And they heard the voice of the Lord God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the Lord God amongst the trees of the garden.

Genesis 12:7 Then the Lord appeared to Abram and said, “To your descendants I will give this land.” And there he built an altar to the Lord, who had appeared to him.

Genesis 17:1 When Abram was ninety-nine years old, the Lord appeared to Abram and said to him, “I am Almighty God; walk before Me and be blameless.

Genesis 18:1 Then the Lord appeared to him by the terebinth trees of Mamre, as he was sitting in the tent door in the heat of the day.

Genesis 26:2 Then the Lord appeared to him and said: “Do not go down to Egypt; live in the land of which I shall tell you.

Genesis 26:24 And the Lord appeared to him the same night and said, “I am the God of your father Abraham; do not fear, for I am with you. I will bless you and multiply your descendants for My servant Abraham’s sake.”

Genesis 35:7 And he built an altar there and called the place El Bethel, because there God appeared to him when he fled from the face of his brother.

Genesis 35:9 Then God appeared to Jacob again, when he came from Padan Aram, and blessed him.

Genesis 48:3 Then Jacob said to Joseph: “God Almighty appeared to me at Luz in the land of Canaan and blessed me,

Exodus 3:2 And the Angel of the Lord appeared to him in a flame of fire from the midst of a bush. So he looked, and behold, the bush was burning with fire, but the bush was not consumed.

Exodus 3:16 Go and gather the elders of Israel together, and say to them, ‘The Lord God of your fathers, the God of Abraham, of Isaac, and of Jacob, appeared to me, saying, “I have surely visited you and seen what is done to you in Egypt;

Exodus 6:1-2 Then the Lord said to Moses, “Now you shall see what I will do to Pharaoh. For with a strong hand he will let them go, and with a strong hand he will drive them out of his land.” 2 And God spoke to Moses and said to him: “I am the Lord. 3 I appeared to Abraham, to Isaac, and to Jacob, as God Almighty, but by My name Lord[a] I was not known to them.

a. Hebrew YHWH, traditionally Jehovah

One example is:

Deuteronomy 32:43 (NIV)
⁴³ Rejoice, you nations, with his people,
   for he will avenge the blood of his servants;
he will take vengeance on his enemies
   and make atonement for his land and people.

Which we know from Hebrews 1:6 is referring to Christ.

However, I suspect that Jesus was referring to the fact that much of Mosaic law was a type, or shadow, of Christ and the new covenant. The book of Hebrews deals with this extensively, and deals with how Christ is the fulfilment of the law.

Hebrews 8:4-5 (NIV)
⁴ If he were on earth, he would not be a priest, for there are already priests who offer the gifts prescribed by the law. ⁵ They serve at a sanctuary that is a copy and shadow of what is in heaven. This is why Moses was warned when he was about to build the tabernacle: “See to it that you make everything according to the pattern shown you on the mountain.”

Hebrews 10:1 (NIV)
¹ The law is only a shadow of the good things that are coming—not the realities themselves. For this reason it can never, by the same sacrifices repeated endlessly year after year, make perfect those who draw near to worship.

Some examples are:

• The promised land (God's rest) was a shadow of salvation (Hebrews 4)
• Animal sacrifices were a shadow of Christ's sacrifice (especially the passover Lamb)
• High priests were a shadow of Christ as our High Priest (Hebrews 5)
• The tabernacle was a shadow of the tabernacle in heaven, where Jesus is our High Priest (Hebrews 8)

As soon as I posted this question, my mind went to the famous story of Jacob's ladder, in Genesis 28:10-22. Two verses in particular stick out for me:

He had a dream in which he saw a stairway resting on the earth, with its top reaching to heaven, and the angels of God were ascending and descending on it.

Verse 12. This is because Jesus is our bridge to Heaven, and He appeared to confirm this reference in John 1:51:

He then added, “I tell you the truth, you shall see heaven open, and the angels of God ascending and descending on the Son of Man.”

And, of course, we have the famous prophetic act of Abraham sacrificing Isaac in Genesis 22:1-19, representing God sacrificing His Son Jesus for us.