The Latter-day Saints were growing in numbers in Nauvoo, and no building could accommodate the large groups of Saints until the Nauvoo Temple was partially done. During the warm summer months the Saints would gather in groves in the "open air" and in smaller groups they would gather in homes or public buildings.
The Temple Stand was usually called "the stand", because leaders or speakers stood or sat on a portable platform or stand. The audience members would sit on split log benches or on the grass around the area. This area was sometimes called "the grove" because it was a small grove of trees that provided shade. Joseph Smith called the area the "temple stand" because it was located on the brow of the hill, near the temple.
Joseph Smith gave a sermon at "the stand" on June 11, 1843 on the Godhead and on the gathering the Jews. It was the first of three important discourses Joseph Smith delivered about the Godhead.
The Temple Stand was the first and most used open-aired meeting place in Nauvoo from October 1839 to April 1844. The Saints also used the grove east of the temple for 15 months from April 6, 1844 to June 28, 1845. The temple was also used occasionally for meetings as early as October 1842 but not on a regular basis until the last year before the Saints left Nauvoo.
More Nauvoo Sites
"Sacred laces Ohio and Illinois" by LaMar C. Berrett, Keith W. Perkins, and Donald Q. Cannon p. 169 and 174