thy gates shall be open. Hebrew they shall keep thy gates open. The word "they" is impersonal: i.e. they who are continually bringing the exiles with their riches. Compare the same idiom in Luke 12:20, "they demand thy soul".
not be shut. These coming times are already being foreshadowed, for this has already been the case for the past few years. This looks beyond the Ezra- Nehemiah period, for see Nehemiah 13:19.