Isaiah 19:22 And the LORD will strike Egypt, striking and healing, and they will return to the LORD, and he will listen to their pleas for mercy and heal them.
Is Isaiah talking about the Jews or Egyptians? Why will they return? Or both?
The antecedant of the plural pronoun "they" is "Egypt".
The material in Isa 19 is in two parts:
This prophecy actually a number of specific predictions that need not delay us now but notice that all these things will occur "on that day" (V16) a common phrase in the OT for either the first or second advents of Jesus, mostly, the second. Almost none of these prediction have occurred up to the present and so will presumably occur when the LORD returns to earth.