The word "multiply" explains how God would make Jacob "fruitful." AT: "give you many children and descendants" (See: [[rc://en/ta/man/translate/figs-doublet]])
This speaks about blessing someone as if a blessing were an object that a person can give. The abstract noun "the blessing" can be stated as "bless." AT: "May God bless you and your descendants as he blessed Abraham" or "May God give to you and your descendants what he promised to Abraham" (See: [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-abstractnouns]])
God giving the land of Canaan to Jacob and his descendants is spoken of as if a child were inheriting money or possessions from his father. (See: [[rc://en/ta/man/translate/figs-metaphor]])