Jacob 2:28–32 says the Lord will command people to practice polygamy at specific times.
Jacob 2:28–32, The Book of Mormon, The Church of Jesus Christ of Latter-day Saints, accessed April 27, 2023
28 For I, the Lord God, delight in the chastity of women. And whoredoms are an abomination before me; thus saith the Lord of Hosts.
29 Wherefore, this people shall keep my commandments, saith the Lord of Hosts, or cursed be the land for their sakes.
30 For if I will, saith the Lord of Hosts, raise up seed unto me, I will command my people; otherwise they shall hearken unto these things.
31 For behold, I, the Lord, have seen the sorrow, and heard the mourning of the daughters of my people in the land of Jerusalem, yea, and in all the lands of my people, because of the wickedness and abominations of their husbands.
32 And I will not suffer, saith the Lord of Hosts, that the cries of the fair daughters of this people, which I have led out of the land of Jerusalem, shall come up unto me against the men of my people, saith the Lord of Hosts.