On what do you base the idea that Jesus (and the 12?) spoke Hebrew?
We used to razz the NT prof at seminary that Hebrew was the language spoken in heaven (because Paul said he heard a voice speaking the the Hebrew dialect) and he insisted (but did not explain) that it was Aramaic.
My Brown,Driver,Briggs Hebrew lexicon says that KePh (= rock) is unattested in the OT and is only found in the plural in two places Jeremiah 4:29 and Job 30:4. The little entry speculates that it is a loan word from Aramaic.
As I say, FWIW.
For one thing, the outright hatred of all things Greek by the Jews in the times post Antiochus Epiphanes... It is a primal thing - So the idea that the Jews would blithely accept Greek is just preposterous.
Secondly, that same sort of disgust was present due to the Samaritans and others wrt the Aramaic language.
Thirdly, if one has ever spent much time with Jews, one would be very well assured of the fact that, as a people, the Jews do not give up their culture in any great degree, no matter what influence is put upon them. This is evident even now, thousands of years after their diaspora into the nations. They might learn Greek, Latin, and Aramaic for purposes of business and communication, but I doubt very much that they would have given up their own language at_all.
Lastly, and most importantly, the Gospel was directed FIRST to the Jews. It is highly important that the disciples were actual (and anointed) scribes in order to even approach them with a written Scripture - It would have been wholly ignored otherwise. Matthew, being a Levite (or of Levi) is the obvious scribe to the Jews, as he was most probably anointed for that purpose as a simple matter of birth into the tribe of Levi.
(Jesus would likewise have to be anointed in order to appoint scribes... as a legal matter... Which puts a particular emphasis upon His anointing in the house of Simon, the chief house of Benjamin... and points directly to Mary Magdalene as being the "woman of the city" who performed that act.)
There is quite a bit of evidence that goes contrary to popular belief, but one has to think like a Jew, not a Roman... Something I am just beginning to understand.
Here is a little bit to get you started:
Ancient-Hebrew.org: "Semitic Origins of the New Testament"
**Note: I do not necessarily endorse this site... I don't know it. It just has a simple layout that shows my argument.