Mormon previewed this story when he introduced Amulek in Alma 8:20, but he left the details to be expanded in Amulek’s sermon. The first interesting phrase in this story is that the appearance of an angel came as Amulek was journeying to see a “very near kindred.” He doesn’t define who that was. There is evidence in the Book of Mormon that kindred tended to live together. However, that wouldn’t require journeying. It is also typical for the wife to move to the land of the husband. Thus, a reasonable speculation is that he was going to see a near female relative who lived among her husband’s kin.
The angel tells Amulek that a prophet will ask him for food, which is precisely what we learned in Alma 8:19. Here the question isn’t repeated, only that he met the man and took him to his house. As a good storyteller would, Amulek builds the story before revealing that the holy man was Alma, “this same man who has been speaking unto you concerning the things of God.” Amulek testifies that Alma is a man of God, and that he knows this because an angel declared it to him.