To answer the question posed on this thread:
8 But ye shall receive power, after that the Holy Ghost is come upon you: and ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth. Acts 1:8.
The message was to the children of Israel who lived outside Israel, whether in Jerusalem, or Judaea, or Samaria, or the uttermost part of the earth.
Spoken from the Mount of Olives Jerusalem was west, Judaea was south, Samaria was north, and the uttermost part was east, or towards the Orient, where God had scattered His people. It was to tell them Messiah/Christ had come, and this is the specific message Messiah has given to God's Chosen people Israel.
To the "Jew" FIRST.