Reynolds Cahoon — Revelation of the Name of the Brother of Jared

In 1834, while residing in Kirtland, Reynolds Cahoon presented his newborn son to the Prophet Joseph Smith to receive a father's blessing and be named. During the administration of the blessing, Joseph Smith gave the child the name 'Mahonri Moriancumer.' After the blessing, Cahoon asked the Prophet where he had obtained that name, as it was unfamiliar. Joseph Smith replied that it was the name of the Brother of Jared, which the Lord had revealed to him. This event is the primary historical source for the name of the Book of Mormon figure who had previously been referred to only by his relationship to Jared.

Fuller account of this event (as retold in Brother of Jared, Juvenile Instructor, Vol. 27, No. 9 (1 May 1892)):

While residing in Kirtland Elder Reynolds Cahoon had a son born to him. One day when President Joseph Smith was passing his door he called the Prophet in and asked him to bless and name the baby. Joseph did so and gave the boy the name of Mahonri Moriancumer. When he had finished blessing and naming the child, Elder Cahoon asked the Prophet where he got that name. 'Why,' said the Prophet, 'that is the name of the Brother of Jared; the Lord has just told me.'