What's happening
This revelation answers the question Show us thy will, O Lord, concerning the Twelve — directing that the vacancies in the Quorum be filled, naming the new Apostles, and appointing them to depart on a mission over the great waters the next spring, taking their leave from the temple site at Far West on a fixed date: April 26, 1839.
It was given at Far West on July 8, 1838 (the same day as Section 117). The Quorum of the Twelve had been thinned by apostasy. The Lord directs that it be filled up (v. 1), names the men to replace those who had fallen — John Taylor, and John E. Page, and Wilford Woodruff, and Willard Richards (v. 6) — and commands the Twelve to take their leave of my saints in the city of Far West, on the twenty-sixth day of April next, on the building-spot of my house (v. 5), to go forth over the great waters and promulgate my gospel. The date and place were specific — and they became a test of faith, because by April 1839 the saints had been driven from Missouri, and Far West was in the hands of mobs.
Let the Twelve be filled (verses 1–6)
Verily, thus saith the Lord: Let a conference be held immediately; let the Twelve be organized; and let men be appointed to supply the place of those who are fallen. — D&C 118:1
The Lord directs that the Quorum, depleted by apostasy, be made whole again. He names the four new Apostles plainly: John Taylor, and John E. Page, and Wilford Woodruff, and Willard Richards (v. 6) — men who would become pillars of the Church (Taylor and Woodruff both later serving as President of the Church). The continuity of the Twelve does not depend on the faithfulness of any one man; when some fall, others are called, and the Quorum endures.
Next spring, from the temple site (verses 4–5)
And next spring let them depart to go over the great waters, and there promulgate my gospel, the fulness thereof, and bear record of my name. Let them take leave of my saints in the city of Far West, on the twenty-sixth day of April next, on the building-spot of my house, saith the Lord. — D&C 118:4–5
Here is the section's famous test. The Lord fixed a date — the twenty-sixth day of April next — and a place — the building-spot of my house, the temple cornerstone site at Far West. By the time that date arrived, the saints had been expelled from Missouri under Governor Boggs' extermination order; Far West was hostile ground, and enemies had openly boasted that this one revelation, at least, could not be fulfilled, since the Mormons had been driven out. But on the night of April 25–26, 1839, the Twelve quietly returned to Far West, met at the temple site before dawn, ordained the new Apostles, rolled a cornerstone into place, prayed, and took their formal leave for their mission to England — fulfilling the revelation to the very day and place. It became a watchword of the Restoration: the word of the Lord does not fail, even when men have sworn it cannot stand.
How the section is built
Six verses, a charge to the Quorum. It opens with the filling of the Twelve (vv. 1–2): hold a conference, organize the Quorum, appoint men to replace the fallen. It gives the commission (vv. 3–4): go over the great waters next spring and promulgate the gospel. It fixes the time and place (v. 5): April 26, 1839, on the building-spot of the temple at Far West. And it names the new Apostles (v. 6): Taylor, Page, Woodruff, Richards. The architecture is brief and exact — and the exactness is the point: a date and a place named in advance, kept against every obstacle, so that the keeping became a witness.
How this sits in the documentary record
Where this lands
Section 118 is short, but it carries one of the clearest demonstrations in the Restoration that the word of the Lord holds even when circumstance has made it look impossible. The Lord named a date and a place — the twenty-sixth day of April next, on the building-spot of my house in Far West — for the Twelve to begin their mission. Then everything went wrong: the saints were driven from Missouri at gunpoint, Far West fell into enemy hands, and the Church's foes openly crowed that this prophecy, at least, was dead, because no Latter-day Saint would dare set foot in Far West again. And yet, in the dark hours before dawn on the appointed day, the Twelve slipped back into the hostile town, met at the temple cornerstone, ordained Wilford Woodruff and the others, and took their leave for England — exactly as the Lord had said, to the very date and spot. The keeping of it, against everything, became its own testimony.
There is a pattern in that worth holding onto. God's promises are often fixed in advance and then tested by events that seem to make them impossible — and the faithful are asked to act on the word anyway, trusting that the Lord can keep what He has spoken even when the way is closed. The Twelve did not wait for Far West to be safe; they obeyed the word and went, and the obedience opened the door. And the fruit was extraordinary: the mission to England gathered thousands and strengthened the whole Church in its hour of greatest weakness. Section 118 is the quiet assurance that when the Lord names a thing, He will bring it to pass — and that our part is to keep faith with His word, on the appointed day, whatever the world has sworn cannot be done.