Genesis 48:6

And the children which you shall beget hereafter, shall be in the name of their brethren; they shall be named after their inheritances.

And thy issue, which thou begettest after them, shall be thine, and shall be called after the name of their brethren in their inheritance.

Your offspring, whom you become the father of after them, will be yours. They will be called after the name of their brothers in their inheritance.