בָּעֵת הַהִיא אָבִיא אֶתְכֶם וּבָעֵת קַבְּצִי אֶתְכֶם כִּי אֶתֵּן אֶתְכֶם לְשֵׁם וְלִתְהִלָּה בְּכֹל עַמֵּי הָאָרֶץ בְּשׁוּבִי אֶת שְׁבוּתֵיכֶם לְעֵינֵיכֶם אָמַר ה'
“At that time I will bring you in, and at that time I will gather you, for I will cause you to be a name and a praise among all the peoples of the Earth when I turn your captivity before your eyes,” says Hashem.
This verse is cited in its entirety at the end of the prayer “You are Hashem, our G-d” in the preliminary morning service. The Metzudas David explains that “At that time I will bring you in” refers to the ten “lost” Tribes. They were not restored to the land of Israel during the time of the second Temple but they will be brought in at the time of the redemption. “At that time I will gather you” refers to the Kingdom of Judah (i.e., the other two Tribes). Not all of them returned in the time of the second Temple but all of them will gathered to Israel at the time of the redemption.