After being directed by the Lord, Ammon tells king Lamoni that he is going to Middoni to deliver his brethren from prison. King Lamoni then offers to go with Ammon, saying: "the king of the land of Middoni, whose name is Antiomno, is a friend unto me; therefore I go . . . that I may flatter the king" (Alma 20:4).
According to Brant Gardner, here in Alma 20 we have another somewhat unusual set of circumstances for which there is a clear Mesoamerican precedent. It is very important to understand that we are not likely speaking here of true friends in the modern sense of the word. They may certainly be friendly, but these are two kings, and rule over different cities. In the Mesoamerican context where we are placing the events of the Book of Mormon, such a "friend" is an ally. City-states in Mesoamerica were frequently at war with other cities. Alliances were forged and broken. Among the allied kings, however, there were frequently formal visits to allied cities that had strong political overtones.
Thus when Lamoni declares Antiomno as a friend, he is more probably indicating that this is an ally with whom there are some mutual expectations. The travel of a king from one city to another city was an occasion that in later years would be sufficiently significant to commission a record in stone. This is no casual meeting of friends who went bowling together every Tuesday. This was a formal exchange of state. It is in this very formal setting that we must understand the nature of the "flattery" that Lamoni suggested that he use to free Ammon's brethren. This is very much a political negotiation, and one that was to be handled with some delicacy, as Lamoni would be asking a king to reverse a decision to imprison the Nephites. [Brant Gardner, "A Social History of the Early Nephites," delivered at the FAIR Conference, August 17, 2001, pp. 10-11]