The internal consistency in the Book of Mormon is a great testimony to its authenticity. As Alma speaks of remembering the captivity of his fathers, he is giving us another example of that consistency. When the angel first appeared to Alma, he instructed him to remember the captivity of his fathers (Mosiah 27:16). Alma never forgot this instruction. Rather, he invited the people of Zarahemla to remember the captivity of their fathers (Alma 5:5). He tells us in this verse that he has not forgotten the mercies of the Lord to his fathers. He repeats this same concept when teaching his son, saying, I would that ye should do as I have done, in remembering the captivity of our fathers (Alma 36:2). See also Alma 36:29. So, we see that this theme was important to Alma, and he sprinkled this concept throughout the Book of Mormon with such internal consistency that we are forced to confess, "this can't be the work of any man."