The word “apostle” comes from a Greek adjective meaning, “one sent forth or dispatched.” The Jews had an equivalent term, shaliakh. One of the rabbinic titles for the High Priest was “the envoy, the shaliakh, the apostolos, of the merciful.” The term focuses more on the person doing the sending than on the one sent. The religious council in Jesus’ time expected every teacher to have delegated authority. That is why they asked Jesus (Yeshua‘) in whose authority He spoke and acted. In John’s gospel, Jesus spoke often of being sent by His Father.
Apostle in Greek:
Strong’s Concordance number: 652
Bible reference: Heb. 3:1
Therefore, holy brethren, partakers of a heavenly calling, consider Jesus, the Apostle and High Priest of our confession. (Hebrews 3:1)