3 Nephi 21:5

therefore, when these works, and the works which shall be wrought among you hereafter, shall come forth from the Gentiles unto your seed, which shall dwindle in unbelief because of iniquity:

So when these works and the works done among you later come from the nations to your children, your children will turn away from believing because of sin.

So when these works—and the works that will happen among you later—come from the Gentiles to your descendants who’ve fallen into unbelief because of their wickedness,