The revelation that forms the basis of the Latter-day Saint dietary code refers to its contents as “a word of wisdom for the benefit of the Saints in these last days” (D&C 89:1). The Word of Wisdom was treated like its name implies during much of the nineteenth century—wide advise from God, but not a commandment. Today, however, parts of it are treated as a commandment—one that can result in being barred from the temple and Church callings if not followed. How did the Word of Wisdom become a commandment? It is surprisingly difficult to nail down a specific point in time in which this occurred. Three main options do emerge from my study of the issue, however: it was either always considered a commandment, the Latter-day Saints voted on and accepted it as a commandment, or it became a commandment when it began to be enforced.
The first option is that the revelation was always considered a commandment. Many of the earliest Saints to receive it treated it as such—recollections of Kirtland and the eastern United States during the 1830s include many accounts where people threw their tobacco pipes in the fire or gave up coffee, tea and liquor for life like John Tanner did. At a meeting of the Kirtland High Council on 20 February 1834, Joseph Smith declared “that no official member in this church is worthy to hold an office after haveing the words of wisdom properly taught to him, and he, the official member, neglecting to comply with, or obey them” which was confirmed by vote. Further evidence exists, such as one rather bizarre incident where a man thought to be possessed with a demon underwent an exorcism in Kirtland and made a covenant that he and his family would observe the Word of Wisdom. When his symptoms returned later, it was blamed on indulging in proscribed substances. Based on evidence like this, BYU professor Paul Y. Hoskisson argued that Latter-day Saints in the Kirtland area treated the Word of Wisdom as a commandment from the start, but when they joined the Saints in Missouri (where it hadn’t been treated as a commandment) and then fled to Nauvoo, strict enforcement of the principle lapsed until the early 20th century.
There are two main reasons early Saints may have treated the Word of Wisdom as a commandment rather than advice. The first three and a half verses of the revelation’s text (the section of the revelation that calls it a word of wisdom) were not always presented as a part of the revelation. When they functioned as an italicized introduction (as in the first edition of the Doctrine and Covenants), the text begins with “behold verily thus Saith the Lord unto you”, and goes straight into saying what is good and not good. That makes it sound very much like a commandment from God with a human-added introduction. Second, early Church leaders like Hyrum Smith and Brigham Young argued that if it is good advice from God Himself, it should be treated as more than just good advice. In either case, the Word of Wisdom can possibly be considered a commandment from the very start.
The second option for the Word of Wisdom becoming a commandment is that a vote occurred in which the general membership of the Church accepted it as such. When Church leaders at the turn of the twentieth century wanted to enforce the principle more strictly, they often referred to Brigham Young declaring it to be a commandment. Most frequently, a general conference in 1851 has been referenced for this. According to the record of this meeting:
The Patriarch [John Smith] again rose to speak on the Word of Wisdom, and urging on the brethren to leave off using tobacco, &c.
President Young rose to put the motion and called on all the sisters who will leave off the use of tea, coffee, &c., to manifest it by raising the right hand; seconded and carried.
And then put the following motion; calling on all the boys who were under ninety years of age who would covenant to leave off the use of tobacco, whisky, and all things mentioned in the Word of Wisdom, to manifest it in the same manner, which was carried unanimously. …
President Young amongst other things said he knew the goodness of the people, and the Lord bears with our weakness; we must serve the Lord, and those who go with me will keep the Word of Wisdom, and if the High Priests, the Seventies, the Elders, and others will not serve the Lord, we will sever them from the Church. I will draw the line, and know who is for the Lord and who is not, and those who will not keep the Word of Wisdom, I will cut off from the Church; I throw out a challenge to all men and women.
It is plausible that this was a vote by the Church to accept the Word of Wisdom as a commandment. President Young’s remarks do seem to support the idea, which is why many general authorities and Church publications referred to this as the time it became a commandment throughout the 20th century.
There are complications here with regarding 1851 as the commandment-making moment. Much like his predecessor, Brigham Young didn’t use Church discipline to enforce the Word of Wisdom, even after declaring it a requirement for Church callings or membership. When President Young encouraged the Saints to follow the Word of Wisdom, he based his logic either on economics (the money can be used better elsewhere) or on the idea that following directions from God leads to eternal life and not following them leads to spiritual darkness. One would think that if he though the 1851 vote made it binding as a commandment, he would have referred to it in subsequent years instead. Further, the event happened nearly 70 years before the Church consistently began to enforce the principle, weakening its stance as the moment it became a commandment. Hence, other times have been suggested for the moment the Word of Wisdom became a commandment.
The next most common date suggested is the October 1908 general conference. Joseph Fielding Smith claimed that Brigham Young had led the Latter-day Saints to accept the Word of Wisdom as a divine commandment in 1851 and that President Joseph F. Smith reiterated this exact same vote in 1908. Likewise, Boyd K. Packer claims that “in 1908 in a general conference … a vote to accept it [the Word of Wisdom] as binding upon the members of the Church was unanimously passed.” The problem is that the 1908 vote wasn’t to accept the Word of Wisdom as a commandment. In the conference report, we read:
Believing in the words and teachings of President Joseph F. Smith as set forth this morning on the subject of temperance, it is proposed, therefore, that all officers and members of the Church of Jesus Christ of Latter-day Saints will do all in their power, that can properly be done, with lawmakers generally to have such laws enacted by our legislature, soon to be elected, as may be necessary to close saloons, otherwise decrease the sale of liquor and enact what is known as the “Sunday Law.” On motion, the immense congregation voted in favor of the resolution submitted, proclaiming “aye” in a unanimous shout.
Although President Smith had spoken that morning about how Latter-day Saints needed to follow the Word of Wisdom as a commandment (because Brigham Young had declared it “to be in force as a commandment thereafter to the Latter-day Saints”), the actual vote was to support laws that banned liquor and sabbath-breaking, not to accept the Word of Wisdom as a binding commandment. Thus, 1908 should probably not be referenced as a time when Latter-day Saints voted to accept the Word of Wisdom as a divine commandment.
The Word of Wisdom ultimately began to be treated as a commandment when it began to be enforced. Somewhere between 1919 and 1921, the First Presidency made adherence to the Word of Wisdom a requirement to attend the temple. As historian Thomas G. Alexander has pointed out, there is not evidence to indicate that there is a specific revelation (or vote, for that matter) backing up this change—only references to statements by earlier authorities, most notably President Brigham Young. From what I have seen, they felt that they were merely giving teeth to something that had already been upgraded to a commandment by President Young. A desire to use the Word of Wisdom as boundary maintenance in the post-polygamy era or to gain respect from Evangelical Protestant Christians that were campaigning for temperance and prohibition may have also played into the decision to make the Word of Wisdom a requirement for attending the temple. For most Latter-day Saints, this was the time at which the Word of Wisdom really began to be treated as a commandment.
These are some of the narratives that have been suggested for how the Word of Wisdom became a commandment. My own perspective is that early Church leaders, including Joseph Smith, Hyrum Smith and Brigham Young, believed that the revelation was the word of God and should be followed (even if they failed to do so personally or bent the requirements for medical purposes). Because of this belief, they attempted to enforce the Word of Wisdom from time to time but failed to successfully implement it on a church-wide level. Later Church leaders remembered these efforts and felt their predecessors had elevated the Word of Wisdom to a commandment. These later leaders then found ways to enforce the principle more fully. Regardless of how it became a commandment for members of the Church of Jesus Christ of Latter-day Saints, the Word of Wisdom is treated as a test of full membership in the Church today and will likely remain so for the foreseeable future.
 “Minutes, 20 February 1834,” p. 40, The Joseph Smith Papers, accessed September 27, 2019, https://www.josephsmithpapers.org/paper-summary/minutes-20-february-1834/2. When Church leaders in Missouri were brought up for trial, one of the main accusations made against them was a failure to observe the Word of Wisdom. Note, however, that Joseph and Emma Smith didn’t always strictly observe the Word of Wisdom themselves, which may have undermined this decision.
 See “Demoniac in Kirtland”, The Zerah Pulsipher Project, accessed 9/23/2019 https://sites.google.com/site/thezerapulsipherproject/contexts/demoniac-in-kirtland?authuser=0. See also W. Paul Reeve, “‘As Ugly as Evil’ and ‘As Wicked as Hell’: Gadianton Robbers and the Legend Process among the Mormons.” Journal of Mormon History Vol. 27, No. 2 (2001): 125-149.
 Paul Y. Hoskisson, “The Word of Wisdom in Its First Decade,” Journal of Mormon History 38 no.1 (2012), 131-200. https://digitalcommons.usu.edu/cgi/viewcontent.cgi?referer=https://www.google.com/&httpsredir=1&article=1068&context=mormonhistory
 See historical introduction at “Revelation, 27 February 1833 [D&C 89],” p. , The Joseph Smith Papers, accessed September 23, 2019, https://www.josephsmithpapers.org/paper-summary/revelation-27-february-1833-dc-89/1
 Brigham Young, for example, said in 1869: “I know that some say the revelations upon these points are not given by way of commandment. Very well, but we are commanded to observe every word that proceeds from the mouth of God” (JD 13:3, https://jod.mrm.org/13/1).
Hyrum Smith stated in 1842 that: “God only is acquainted with the fountain of action, and the main springs of human events; he knows where disease is seated, and what is the cause of it. … He knows what course to pursue to restore mankind to their pristine excellency and primitive vigour, and health; and he has appointed the word of wisdom as one of the engines to bring about this thing. … We are told by some that circumstances alter the revelations of God—tell me what circumstances would alter the ten commandments? they were given by revelation—given as a law to the children of Israel;—who has a right to alter them? They are too small for us to notice, they are not too small for God to notice, and have we got so high, so bloated out, that we cannot condescend to notice things that God has ordained for our benefit? or have we got so weak that we are not fit to be called saints? for the word of wisdom is adapted to the capacity of all that ‘(are) or (can be called saints).’ Listen not to the teaching of any man, or any elder who says the word of wisdom is of no moment; for such a man will eventually be overthrown.” (see Times and Seasons, Vol. 3, No. 15, pp. 799-801).
 For example, in April 1908 President Francis M. Lyman of the Quorum of the Twelve stated that: “In the beginning, [the Word of Wisdom] was not laid down as a strict commandment. I do not know whether or not the Lord took into account the fact that our forefathers, and our fathers, had been so used to many things forbidden in the Word of Wisdom that it might be difficult for them to order their lives in harmony with those requirements: so we were given . . . years of training and experience before the Lord announced, through His servant the Prophet Brigham Young, that the Word of Wisdom has now become a commandment of the Lord. President Young laid it down very strictly and exactly from this stand that from that time henceforth the Word of Wisdom is a commandment from the Lord, and all Latter-day Saints are required to observe it.” (Francis M. Lyman, CR, April 1908.)
 See, for example, https://www.churchofjesuschrist.org/manual/doctrine-and-covenants-student-manual/section-89-the-word-of-wisdom?lang=eng and https://www.churchofjesuschrist.org/study/manual/doctrine-and-covenants-student-manual-2017/chapter-35-doctrine-and-covenants-89-92?lang=eng.
 See Brigham Young and John A. Widtsoe (ed.) Discourses of Brigham Young (SLC: Deseret Book Company, 1977), 182-187.
 Joseph Fielding Smith, Answers to Gospel Questions, 1:196.
 Boyd K. Packer, “The Spirit of the Tabernacle,” Ensign, May 2007.
 Conference Report, October 1908, pp. 64-65.
 See Thomas G. Alexander, Mormonism in Transition: A History of the Latter-day Saints, 1890-1930, 3rd ed. (SLC: Greg Kofford Books, 2012), 279. Alexander dates the temple requirement in 1921. The most recent Doctrine and Covenants Institute Student Manual puts the date at 1919 (https://www.churchofjesuschrist.org/study/manual/doctrine-and-covenants-student-manual-2017/chapter-35-doctrine-and-covenants-89-92?lang=eng).
 Thomas G. Alexander, Mormonism in Transition: A History of the Latter-day Saints, 1890-1930, 3rd ed. (SLC: Greg Kofford Books, 2012), 282.