Around 130 AD, Papias, bishop of Hieropolis in Asia Minor, wrote, "Matthew compiled the sayings [of the Lord] in the Aramaic language, and everyone translated them as well as he could." (Aramaic was very close to Hebrew.)
Around 180 AD, Irenaeus of Lyons wrote: "Matthew also issued a written Gospel among the Hebrews in their own dialect."
Although Paul was literate in Hebrew, most --- but not all --- scholars think his original autographs in Koine Greek.
But that wasn't the question. We were discussing whether Hebrew was the common spoken vernacular language of the 1st century Jewish people, the language Jesus spoke. It was not. Jesus' and His Jewish neighbors' spoken language was Aramaic.
By that time (the 1st Century) Hebrew was almost exclusively a written language. People outside of Jerusalem itself rarely or never used it conversationally.
As of the first century AD:
Jewish daily conversational language throughout the Middle East: Aramaic.
Plus, an educated religious Jewish man who was also a commercial traveler and/or a Roman citizen (like Paul) would be reasonably adept in all three languages: Aramaic face-to-face with other Jews, spoken; Hebrew and Greek written. And probably he could manage in spoken Latin as well, like in his frequent dealings with the Roman authorities.
Paul was a highly gifted man.
More so, he was educated in Hebrew, as a candidate for the Sanhedrin, for which he was studying with Gamaliel. But after his conversion, he was sent back to Tarsus, a cosmopolitan university city, to study the languages and culture of the Gentiles so as to be an effective itinerant evangelist to all manner of them. His time there in Tarsus was eleven years for this purpose. However, he was born as a Roman citizen of parents whose heritage was having been awarded citizenship for their services to the Emperor.
While Jesus doubtlessly chose unschooled men of his locality to demonstrate that ordinary men outside of the Jewish clergy were trainable to be carriers of the good news that "Jesus saves" throughout the Hebrew-dominant regions in Eretz Yisroel and beyond.
But again without question His foresight enabled Him to choose Judas Iscariot and give him every chance for salvation, though knowing that he would fail in commitment, and was to be replaced by a highly-trained pre-selected adversary-tuned-saint fit to write a body of discipline for the management of the churches and their communicants. Paul was schooled by Jesus apart from the other eleven, and commended to his work with the Gentiles by them, having talents that none of them could begin to match, even under Spirit guidance.