Wilford Woodruff records Joseph Smith, Jr. declaring that once the Nauvoo temple is finished ordinances for the living and dead can be performed.
Discourse, 8 April 1844, as Reported by Wilford Woodruff, Wilford Woodruff Papers website, accessed January 31, 2024
the mountain of the Lords House is in the centre of North & South
America, when the house is done, Baptism font erected
and finished & the worthy are washed, anointed, endowed
& ordained kings & priests, which must be done
in this life, when the place is prepared you must
go through all the ordinances of the house of the
Lord so that you who have any dead friends must
go through all the ordinances for them the same as
for yourselves;