Luke 3:23

καὶ αὐτὸς, etc., and He, Jesus, was about thirty years of age when He began. The evangelist's aim obviously is to state the age at which Jesus commenced His public career. ἀρχόμενος is used in a pregnant sense, beginning = making His beginning in that which is to be the theme of the history. There is a mental reference to ἀπ ἀρχῆς in the preface, Luke 1:1; cf. Acts 1:1; “all that Jesus began (ἤρξατο) both to do and to teach”. ὡσεὶ, about, nearly, implying that the date is only approximate. It cannot be used as a fixed datum for chronological purposes, nor should any importance be attached to the number thirty as the proper age at which such a career should begin. That at that age the Levites began full service, Joseph stood before Pharaoh, and David began to reign are facts, but of no significance (vide Farrar in C. G. T.). God's prophets appear when they get the inward call, and that may come at any time, at twenty, thirty, or forty. Inspiration is not bound by rule, custom, or tradition.