By definition a concubine could be either a woman kept for lewd purposes or a lawful wife of a lower social standing than her husband’s other wife or wives (see commentary on Jacob 1:15; Jacob 2:27). Hagar, plural wife of Abraham, would be an example of the latter definition. We have no reason to suppose that there was any sort of a social caste system among the Nephites that would justify the idea that Noah had taken wives of a lower social order. Along with having plural wives, King Noah and his priests (verse 4) also consorted with paramours (see Mosiah 12:29). Their example of “whoredoms and all manner of wickedness ” served to justify and entice their people into similar behavior. As noted earlier, such practices had been condemned by the commandment of the Lord through father Lehi (Jacob 2:34).