After 1885 the Pearl of Great Price was frequently used to explain the priesthood ban. In a letter dated January 13, 1912 the First Presidency wrote, "You are referred to the Pearl of Great Price, Book of Abraham, Chapter 1, versus 26 and 27, going to show that the seed of Ham was cursed as pertaining to the priesthood; and that by reason of this curse they have no right to it."
Lester E. Bush Jr. writes on page 81 of the book Neither White nor Black the following:
"When fully developed the Pearl of Grade Price argument went as follows: Cain became black after murdering his brother Abel; among his descendents were a people of Canaan who warred on their neighbors and were also identified as black. Ham, Noah’s son, married Egyptus, a descendent of this Cain-Canaan lineage; Cain’s descendents had been denied the priesthood, and thus Ham’s descendents were also denied the priesthood. This was confirmed in the case of Pharaoh, he descendents of Ham and Egyptus, and of the Canaanites, and who was denied the priesthood; the modern Negro was of this Cain-Ham-lineage, and therefore was not eligible for the priesthood."
There are several problems with this argument, as Bush goes on to explain.
"Though Cain’s descendents are identified as black at one point before the flood, they are never again identified. The people of Canaan are not originally black and are thus unlikely candidates for Cain’s ‘seed.’ there is no explicit statement that Ham’s wife was ‘Egyptus’; rather the account reads that there was a woman who ‘was the daughter of Ham, and the daughter of Egyptus.’…moreover, the book of Moses records that Ham was a man of God prior to the flood, and the daughters of the sons of Noah were ‘fair.’ the effort to relate Pharaoh to the antediluvian people of Canaan is especially strained, for in characterizing Pharaoh as a descendent of Egyptus and the ‘Canaanites’ there is no suggestion that this letter group was any other than the people of Canaan descended from Ham’s son, Canaan (who also have been cursed).
"How then was the Pearl of Great Price put to such ready use in defense of the policy of priesthood denial to Negroes? Very simply, the basic belief they lineage to be traced from Cain through the wife of Ham to the modern Negro had long been accepted by the Church, independently of the Pearl of Great Price. it was a very easy matter to read this belief into that scripture, for if one assumes that there was a unique continuous lineage extending from Cain and Ham to the present and that this is the lineage of the contemporary Negro, and it must have been accomplished essentially as B.H. Roberts proposed. (pg. 81-82)