John Gills Exposition of the Bible Commentary - Genesis 17:16
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... read more
Matthew Henry's Complete Commentary - Genesis 17:15-22
Here is, I. The promise made to Abraham of a son by Sarai, that son in whom the promise made to him should be fulfilled, that he should be the father of many nations; for she also shall be a mother of nations, and kings of people shall be of her, Gen. 17:16. Note, 1. God reveals the purposes of his good-will to his people by degrees. God had told Abraham long before that he should have a son, but never till now that he should have a son by Sarai. 2. The blessing of the Lord makes fruitful, and... read more