And I will bless her
The Targum of Jonathan adds, "in her body", with fruitfulness, who before was barren, and in her soul with spiritual blessings, and in both with the blessing of eternal life:
and give thee a son also of her;
as he had given him one of Hagar: God had before promised Abraham a son that should be his heir, but he had not till now told him that he should be born of Sarah his wife:
yea, I will bless her;
which is repeated for the confirmation of it, and for the greater strengthening Abraham's faith in it:
and she shall be [a mother] of nations;
of the twelve tribes of Israel; of the two nations of Israel and Judah;
kings of people shall be of her;
as David, Solomon, and others, and especially the King Messiah.