The Prophet Joseph Smith (1805–44) taught that the time for the second gathering of the house of Israel is specifically reserved for the last days:
“The time has at last arrived when the God of Abraham, of Isaac, and of Jacob, has set His hand again the second time to recover the remnants of his people, which have been left from Assyria, and from Egypt, and from Pathros, and from Cush, and from Elam, and from Shinar, and from Hamath, and from the islands of the sea, and with them to bring in the fulness of the Gentiles, and establish that covenant with them, which was promised when their sins should be taken away. … This covenant has never been established with the house of Israel, nor with the house of Judah. …
“Christ, in the day of His flesh, proposed to make a covenant with them, but they rejected Him and His proposals, and in consequence thereof, they were broken off, and no covenant was made with them at that time. …
“Thus after this chosen family had rejected Christ and His proposals, the heralds of salvation said to them, ‘Lo, we turn unto the Gentiles;’ and the Gentiles received the covenant, and were grafted in from whence the chosen family were broken off” (History of the Church, 1:313).