3 Nephi 21:2

And behold, this is the thing which I will give unto you for a sign: for verily, I say unto you, That when these things which I declare unto you, and which I shall declare unto you hereafter of myself, and by the power of the Holy Ghost, which shall be given unto you of the Father, shall be made known unto the Gentiles, that they may know concerning this people which are a remnant of the house of Jacob, and concerning this my people which shall be scattered by them;

Here is the sign I will give you. When the things I tell you now and will tell you later come from me through the Holy Spirit, they will be shared with the nations. The nations will learn about your people who are part of the house of Jacob. They will also learn about your people who will be scattered by them.

Here’s the sign: When the things I’m telling you now—and the things I’ll reveal later through the Holy Spirit the Father gives you—are made known to the Gentiles, they’ll learn about this people, a remnant of Jacob’s family, and about how my people will be scattered by them.