Section 132 requires that a man entering into polygamy only do so with the consent of his wife.Emma struggled deeply with the principle of plural marriage. Joseph introduced the practice carefully and incrementally, marrying many additional wives, each of whom vowed to keep their participation confidential. Little is known about Emma’s knowledge and feelings about these marriages, some of which entailed commitments in this life while others involved commitments for the next life only. Nevertheless, it is apparent that Joseph withheld knowledge of some of these relationships from Emma. When he did share limited information with her, she struggled, shifting her perspective and support over time. In early 1843, Emma appears to have accepted plural marriage and personally consented to and witnessed Joseph’s marriages to four women. But by July, her attitude toward the practice had shifted again, and she burned a manuscript copy of the revelation on plural marriage now found in Doctrine and Covenants 132.
The Letter. You can view actual images of the two page letter at https://www.josephsmithpapers.org/paper ... ical-intro. The letter is in Joseph Smith's handwriting except for the place and date were added by scribe William Clayton. The text, per the josephsmithpapers.org website, is as follows (with footnotes removed; italices added for emphasis
The Criticism. Of course, keeping the Whitneys' visit secret from Emma was to keep Emma from learning about his secret sealing to Sarah Ann Whitney, which contradicts even Section 132 which required that Joseph Smith get Emma's permission first. As historian Todd Compton wroteNauvoo August 18th. 1842>
Dear, and Beloved, Brother [Newel K. Whitney] and Sister, [Elizabeth Ann Smith] Whitney, and &c. [Sarah Ann Whitney]—
I take this oppertunity to communi[c]ate, some of my feelings, privetely at this time, which I want you three Eternaly to keep in your own bosams; for my feelings are so strong for you since what has pased lately between us, that the time of my abscence from you seems so long, and dreary, that it seems, as if I could not live long in this way: and <if you> three would come and see me in this my lonely retreat, it would afford me great relief, of mind, if those with whom I am alied, do love me, now is the time to afford me succour, in the days of exile, for you know I foretold you of these things. I am now at Carlos Graingers [Granger’s], Just back of Brother Hyrams [Hyrum Smith’s] farm, it is only one mile from town, the nights are very pleasant indeed, all three of <you> come <can> come and see me in the fore part of the night, let Brother Whitney come a little a head, and nock at the south East corner of the house at <the> window; it <is> next to the cornfield; I have a room intirely by myself, the whole matter can be attended to with most perfect saf[e]ty, I <know> it is the will of God that you should comfort <me> now in this time of affliction, or not all at all now is the [page break] time or never, but I hav[e] no kneed of saying any such thing, to you, for I know the goodness of your hearts, and that you will do the will of the Lord, when it is made known to you; the only thing to be careful of; is to find out when Emma comes then you cannot be safe, but when she is not here, there is the most perfect safty: only be careful to escape observation, as much as possible, I know it is a heroick undertakeing; but so much the greater frendship, and the more Joy, when I see you I <will> tell you all my plans, I cannot write them on paper, burn this letter as soon as you read it, keep all locked up in your breasts, my life depends upon it, one thing I want to see you for is <to> get the fulness of my blessings sealed upon our heads, &c. you will pardon me for my earnestness on <this subject> when you consider how lonesome I must be, your good feelings know how to <make> every allowance for me, I close my letter, I think Emma wont come to night if she don't don't fail to come to night, I subscribe myself your most obedient, <and> affectionate, companion, and friend.
Compton, In Sacred Loneliness (Salt Lake City: Signature Books, 1997), page 350."[t]he Mormon leader is putting the Whitney's in the difficult position of having to learn about Emma's movements, avoid her, then meet secretly with him" and that the "cloak-and-dagger atmosphere in this letter is typical of Nauvoo polygamy."
The Apologetic. Per FAIRMormon (https://www.fairmormon.org/answers/Jose ... ite_note-3), the letter is addressed to Newel and Elizabeth Whitney and "Etc.", meaning Sarah Ann. With Sarah Ann's parents invited too, how could Joseph Smith be alone with her for a conjugal visit? Smith did not want Emma to know "because she is opposed to plural marriage... hardly  conducive to the spirit" in giving the Whitneys the fullness of Smith's blessings on their heads. The visit was for religious purposes, not sexual. Joseph may not have wanted Emma to know that he was going to seal parents Newel and Elizabeth to one another, since Emma had not yet been sealed to Joseph Smith because of Emma's opposition to polygamy. And finally, Smith may have wanted to avoid involving his friends if he were found by Sheriff King or others looking to take Smith back to Missouri. "Anyone that was searching for Joseph knew that Emma could lead them to him if they simply observed and followed her. If this were the case, the most dangerouss time for the Whitneys to visit Joseph may have been when Emma was there--not necessarily because Emma would have been angered by finding Sarah Ann (after all, Emma did not know about the sealing, and she would have found all three Whitneys there--not just Sarah Ann),... ."
Debunking the Apologetic. Bishop Newel Witney conducted the July 27, 1842 sealing of his daughter, Sarah Ann, to Joseph Smith. Elizabeth Whitney witnessed it. Why would they be opposed to giving their daughter Sarah Ann alone time with her "husband" Joseph for sex during the visit? Smith had been in hiding then for 10 days, which began just 4 days after the sealing. The fact that Sarah Ann's parents would accompany her to the visit does not undermine that Smith's purpose for Sarah Ann to come to where he was was other than for a sexual liason with her. Further, if the blessings (there can be more than one purpose for a visit) were to be for Newel and Elizabeth to get the rest of their blessings, why was Sarah Ann the only Whitney child to come merely to witness it?
Further, and about the 'safety' issue, Joseph Smith was in hiding. If he was concerned that Sheriff King (or others looking for Smith) would learn of Smith's hide out location (Carlos Grainger's house), why is he not writing to implore the Whitneys to convince Emma not to forego a visit to Joseph while he was there? If that's the danger--Sheriff King and others following Emma to his hide-out--the imperative would have been to ask the Whitneys to preserve the secrecy of Smith's hide-out by them encouraging Emma to remain at the Smiths' house in Nauvoo. Rather, Smith wanted the Witneys to stealthily visit him if Emma wasn't going to visit Joseph that night.