[First Presidency to Joseph W. McMurrin]
We find upon inquiry that it has been some years since ordinances bestowing second blessings have been performed in cases where both parties are dead. Where people are sealed in the temple for and on behalf of the dead, or in cases where people who are dead were themselves sealed while living, the feeling has always been that every privilege, power and blessing of every description will be given to them, if they have lived worthy of same, and that they could not have more even if they had additional blessings sealed upon them. We, therefore, feel that there is no necessity of performing the ordinances that Sister Smith requests.
[Source: Heber J. Grant, Anthony W. Ivins, and Charles W. Nibley to Joseph W. McMurrin, Oct. 19, 1926, in Anderson, Devery; The Development of LDS Temple Worship, 1846-2000: A Documentary History, http://amzn.to/TempleWorship]