I do not think this verse relate to Christian era, to Christ etc.
Its a part of the old covenant with Israel. This covenant has ended. Its not about end times.
It does not relate to the Christian era at all . . . it is a promise to Israel that sometime in the future (way after 70 A.D.) that he would gather them from the nations.
Besides, if Jesus were predicting the end of Israel, why did the disciples ask Him to tell them when the kingdom would be restored?
"When they therefore were come together, they asked of him, saying, Lord, wilt thou at this time restore again the kingdom to Israel?" (Acts 1:6).
He can't 'restore' something that did not already 'exist' . . . In David's day.