he = one. But a special various reading called Sevir (App-34), reads "they": i.e. thine exiles. come = come home; as in 1Sa_11:5. Psa_45:15. Pro_2:10, or, into blessing; as in Psa_69:27. Nothing has "fallen out" of the text!
Assyria. See the "enemy", Mic_7:10.
the fortified cities = the cities of Matzor (i.e. the fortress) put for Egypt. Compare Isa_19:6; Isa_19:37.
the river. Put by Figure of speech Synecdoche (of Genus), App-6, for the Euphrates. Also the Figure of speech Antonomasia.