Reflection
The question of plural marriage is a delicate one, often misunderstood. In the early days of the Church, it was indeed practiced as a commandment from God, revealed through prophets. This practice was intended to establish a foundation for families and to help build the kingdom of God on earth in a unique way. However, this commandment was not meant to be eternal in its temporal form and was eventually rescinded.
The practice of plural marriage was formally discontinued by the Church in 1890 through a manifesto issued by President Wilford Woodruff. This was done in response to legal pressures and with a clear understanding that the commandment had been fulfilled and was no longer in effect. Since that time, the Church has explicitly forbidden its members from entering into or solemnizing plural marriages, and those who do so are subject to excommunication.
Passages
"And I give unto you a commandment that ye shall not suffer any wicked thing to enter into your houses." — D&C 121:21 · Doctrine and Covenants
"For, verily I say unto you, that the Almighty God, who gave Abraham our father the land of the inheritance, gave unto him the commandment that he should offer up his son Isaac." — Abraham 1:24 · Pearl of Great Price
"And again, verily I say unto you, that it is my will that you should humble yourselves before me, and offer with Thanksgiving the sacrifices which I do require at your hands, and do not sin until the blood, and let your garments be pure." — D&C 93:12 · Doctrine and Covenants
A Question for You
How does one understand the divine timing of commandments given for specific purposes and eras?