Go through... — Here, probably, we have the cry of the prophet himself (but, possibly, also that of the Servant of Jehovah) addressed to the heralds, who are to go forth and summon the exiles to return to the restored city. On the special phrases, see Notes on Isaiah 40:3; Isaiah 57:14.
Lift up a standard for the people. — Literally, peoples, the plural indicating that the prophet thinks of the Gentile nations as escorting Israel. It follows from this that the command itself is addressed, like the previous clauses, to the returning exiles.