[George Q. Cannon]
There was an interchange of views as to the propriety of admitting persons who had not received their endowments into the Temple to witness marriages. On this point the Prophet Joseph was exceedingly particular. The temple clothing was not to be shown to those who had not received their endowments; but it has become so great a habit to expose the dead to the public gaze that the sacredness of this requirement has faded away. I have for years protested against the exposure of our deceased brethren and sisters dressed in their temple clothing, and we have succeeded at last in stopping these public exhibitions at the meeting houses and confining them to the homes of the deceased persons, and then with the understanding that the clothing shall be covered up. In relation to the question before us we all felt that there was an impropriety in persons, especially adults, being admitted to the Temple who had not had their endowments, when the marriage ceremony is being performed or on other occasions.
[Source: The Journal of George Q. Cannon, Church Historian's Press, https://churchhistorianspress.org/george-q-cannon]