Here again is the redemptive theme of Isaiah. After the destruction of Israel there will come a time for the return of a portion of the house of Jacob. Because this is directed at time period where the carrying away of the ten tribes is occurring, this gathering must also come at the same future time as the final triumph of the Messiah. This is a prophecy for the last days. When these lost of the house of Jacob turn away from the arm of flesh (upon which they have relied, or "stayed") and toward their God, they will be returned not only to their God, but to their community of God's chosen people.
Ludlow notes:
"The concept of a remnant returning is a key theme in Isaiah's writings. It goes back to his initial vision (Isa. 6:13) and remains a thread of hope weaving throughout his darkest pronouncements of doom. Isaiah uses the term remnant to describe two distinct groups of Israelites: he talks about a remnant that remains in the land after the Assyrian destruction and promises the return of a future righteous remnant. The two groups are called the historical remnant and the eschatological remnant respectively. The historical remnant is the group present from a past event (such as the Assyrian invasions), while the eschatological remnant is the group that will emerge from a future action of God and have the qualifications of a latter-day, millennial society. Isaiah's urgent hope is that the historical remnant of the eighth century BC will return to the Lord and become the community from which the eschatological remnant will emerge. (Ludlow, 1982 p. 164.)
This continues the duality of meanings noted for the Messianic passages of the last chapter. It is completely within the normal mode of Isaiah's prophecy to refer to an immediate remnant returning, and yet look forward to the more complete and final reunion of the remnant into the house of Jacob that will come before the Messiah's triumphal return.