Marcan Priority
The gospel of Mathew is just a crudely edited version of Mark – the extra bits were blatantly added to fulfil Jewish prophecy. To most scholars, Marcan priority is the idea that the Gospel of Mark was the first of the three synoptic gospels to be written, and was used as a source (copied and adapted) by the other two (Matthew and Luke).
Over three-quarters of Mark’s content is found in both Matthew and Luke, and 97% of Mark is found in at least one of the other two synoptic gospels. Additionally, Matthew (24%) and Luke (23%) have material in common that is not found in Mark.
All reconstructions are fantasies… I highly recommend the best study on the subject and the amazing AS.
To be fair many educated jews spotted right away that Mathew just added a bunch of stuff that would allow us to follow Christ without rousing rabbis – little did they know the book they wrote was a hit with gentiles, which was a bit lucky (in that it gave rise to the biggest world religion within a few hundred years). Funny old world.
Many say that Mark is more of a sermon version of Mathew – and try not to focus on the idea that Mathew just added a bunch of prophecy fulfilment passages to help woo the jew.
Most scholars agree that Mathew is a propaganda version of Marc that was put in its place at the start of the new testament. Not just fudging it with obvious additions that Jesus was descended from Abraham/Moses/David etc, but also that he got stuck in Egypt, was a Nazarean, and all the other stuff that needed to be ticked in order for existing Jews to accept they had a new messiah on their hands. Pretty obvious to those who actually read the bible in a historic context. Watch this https://www.youtube.com/watch?v=hCyFw3jnoUk
Same story – different spin – blatant that they kept all versions in there – a good way to give a bit of what everyone needs to belive, I guess.