It took hours of sifting through information to assemble what seems to be a logical answer to what some may think is easy. If asked what language Jesus spoke, some people will immediately answer Hebrew, others Aramaic, and even some have said Arabic. I have even heard Greek and Latin.
We know from the Gospels that Jesus, 'Easa in Arabic, spoke to many different people in different places across the Middle East. He spoke to the Romans, and the Jewish high council, and everyday people across all walks of life in places like Palastine, Jordan, Syria, and Lebanon.
According to the Ko'ran, Jesus was given the knowledge of the Torah. Jesus had intimate knowledge of the Jewish traditions and the Mosaic law, the laws passed to Moses. Jesus most likely spoke Hebrew to the scholars in the synagogue, since he spent a lot of time as a youth in the synagogues. According to the Ko'ran and the Bible, Jesus was to bring the message given to him to the children of Israel [and then to the Gentiles]. Jesus reprimanded the Jews for making religion hard to follow. So, it was his duty to lead us to the right path.
I had been under the impression that the Children of Israel spoke Hebrew, but actually Hebrew was not the common language among the Jews of this time. It was mostly a priestly language. Aramaic was the trade language. So, it was the most widely spoken language in the surrounding regions and most likely the language used by Jesus. It is speculative that he may have even spoken some Latin when addressing the Romans.
The Ko'ran states: "We* never sent to a people a messenger who did not master their tongue; so he made himself understood, distinctly expressing all that is meant..."
Another translation: "We* never sent a messenger who did not speak the tongue of his people, that he may explain to them distinctly..."(Surah 14:4)
Here is the most important point; every prophet that has come, spoke the appropriate language to give God's message clearly and accurately. We shouldn't let the squabbling of scholars inhibit or dampen our yearning for knowledge. It is too easy to lose sight of why we began our search when there are so many clouds hiding the sun.
* God is one God and the usage of "we" is the royal "we," also called the singular of intensity.