A solemn assembly is a formal and sacred procedure in the Church of Jesus Christ of Latter-day Saints (LDS Church) conducted to give added emphasis to the purpose of the occasion. Solemn assemblies are held at the dedications of temples and for specially-called meetings to provide instruction to church leaders. Solemn assemblies are also held for the purpose of sustaining a new church president, who church members consider to be a prophet, seer, and revelator. Such assemblies are held, in particular, to follow the law of common consent. In 1831, a year after Joseph Smith established the Church of Christ, church members believe he was instructed by revelation to "call your solemn assembly, that your fastings and your mourning might come up into the ears of the Lord of Sabaoth." Historically, solemn assemblies were held on special occasions of major religious importance in ancient Israel.
Connected with temple dedications
The first solemn assembly connected to a temple dedication in modern times was held on March 30, 1836, as part of the dedication of the Kirtland Temple, the first temple built in the Latter Day Saint movement. Prior to the dedication, Smith taught church members, "We must have all things prepared, and call our solemn assembly as the Lord has commanded us, that we may be able to accomplish His great work, and it must be done in God's own way. The House of the Lord must be prepared, and the solemn assembly called and organized in it, according to the order of the House of God." The dedication of the Kirtland Temple introduced many elements of solemn assemblies connected with temple dedications that are still used today, including the Hosanna Shout and the singing of "The Spirit of God Like a Fire Is Burning," a hymn written by W. W. Phelps. Solemn assemblies have been held in connection with the dedications of all LDS Church temples.
Sustaining new church presidents
At the first general conference after the death of a church president and the calling of his successor, the session at which the sustaining vote takes place is called a solemn assembly. During a solemn assembly sustaining, groups of church members are asked to stand in succession and sustain the new president, along with his counselors and the Quorum of the Twelve Apostles. Historically, the order of the sustaining groups has been: the First Presidency, the Quorum of the Twelve, the Quorums of Seventy and Presiding Bishopric, the remaining Melchizedek priesthood holders, Aaronic priesthood holders, and then all church members together. In more recent solemn assemblies, female church members aged 18 and older who constitute the Relief Society and female church members aged 12 to 18 who constitute the Young Women organization have been asked to stand and vote as distinct groups as well. The order of the April 2018 Solemn Assembly to sustain Russell M. Nelson was changed slightly. The sustaining by Melchizedek Priesthood holders was followed by the Relief Society, then the Aaronic Priesthood, the Young Women, and the church at large.
After the First Presidency votes, the other groups in turn, and then all the members of the church together, including those who have voted previously, are asked to stand wherever they may be at the time and vote in a single call to sustain, or oppose, the new president, along with his counselors and the Quorum of the Twelve. Until the spring general conference of 1973, solemn assemblies included a vote for the sustaining of the Patriarch to the Church (formerly Presiding Patriarch), which office was abolished in 1979. Local seventies were explicitly included as part of the Melchizedek priesthood voting group as well, until the 1986 dissolution of local quorums of seventy at the stake level. The entire procedure until then had lasted a half hour, given that the voting had been done separately for each of the positions being called upon.
The sustaining vote of a solemn assembly is observed by general authorities at gatherings of church members at satellite locations on Temple Square, such as the Salt Lake Tabernacle and the Assembly Hall. The voting is observed by members of stake presidencies at local meetinghouse locations around the world, and observers are asked to invite those who oppose to meet with their stake president.
During the solemn assembly held on April 6, 1973, at which Spencer W. Kimball was sustained as the church's 12th president, N. Eldon Tanner described the purpose and deep spiritual meaning of such occasions for church members: