D&C 135

John Taylor related that - 

"...The same morning, after Hyrum had made ready to go—shall it be said to the slaughter? yes, for so it was—he read the following paragraph, near the close of the twelfth chapter of Ether, in the Book of Mormon, and turned down the leaf upon it:

5 And it came to pass that I prayed unto the Lord that he would give unto the Gentiles grace, that they might have charity. And it came to pass that the Lord said unto me: If they have not charity it mattereth not unto thee, thou hast been faithful; wherefore thy garments shall be made clean. And because thou hast seen thy weakness, thou shalt be made strong, even unto the sitting down in the place which I have prepared in the mansions of my Father. And now I … bid farewell unto the Gentiles; yea, and also unto my brethren whom I love, until we shall meet before the judgment-seat of Christ, where all men shall know that my garments are not spotted with your blood..."   (Doctrine and Covenants 135:4–5)

He then declared -

"...The testators are now dead, and their testament is in force."  (Doctrine and Covenants 135:4–5)