And he took their little children, one by one, and blessed them, and prayed unto the Father for them.. 3 Nephi 17:21

3 Nephi 17:11,21-22

And it came to pass that he commanded that their little children should be brought.
And when he had said these words, he wept, and the multitude bare record of it, and he took their little children, one by one, and blessed them, and prayed unto the Father for them.
And when he had done this he wept again.
3 Nephi 17:11,21-22

Read in scriptures: http://bit.ly/2a5uCvM

...he did teach and minister unto the children...and they did speak unto their fathers great and marvelous things... 3 Nephi 26:14

3 Nephi 26:14,16

And it came to pass that he did teach and minister unto the children of the multitude of whom hath been spoken, and he did loose their tongues, and they did speak unto their fathers great and marvelous things, even greater than he had revealed unto the people; and he loosed their tongues that they could utter.
Behold, it came to pass on the morrow that the multitude gathered themselves together, and they both saw and heard these children; yea, even babes did open their mouths and utter marvelous things; and the things which they did utter were forbidden that there should not any man write them.
3 Nephi 26:14,16

Read in scriptures: http://bit.ly/1ULThaw