*Minor differences ignored. Grouped by changes, with first version listed as example.
Saying, Surely blessing I will bless thee - That is, I will certainly bless thee. The phrase is a Hebrew mode of expression, to denote emphasis or certainty - indicated by the repetition of a word; compare Genesis 14:23; Exodus 8:10; Joel 3:14; Judges 5:30; Judges 15:16.
Multiplying I will multiply thee - I will greatly increase thee - I will grant thee an exceedingly numerous posterity.
Saying, Surely blessing I will bless thee - I will continue to bless thee.
Multiplying I will multiply thee - I will continue to increase thy posterity. In the most literal manner God continues to fulfill this promise; genuine Christians are Abraham's seed, and God is increasing their number daily. See the notes on Genesis 22:12-18 (note); and Genesis 23:1 (note).
Saying, Surely (e) blessing I will bless thee, and multiplying I will multiply thee.
(e) I will heap many benefits on you.
Saying, surely blessing I will bless thee,.... Which is expressive of the certainty of the blessings; the reality and substantiality of them; the abundance of them, and the continuance of the same: and of this nature are all spiritual blessings; as to be chosen of God; to have God to be a covenant God and Father; to be justified, pardoned, adopted, and sanctified, and so have a right and title to eternal happiness:
and multiplying I will multiply thee; meaning both in his natural and spiritual seed, which has had its accomplishment.
multiplying . . . multiply--Hebraism for superabundantly multiply.
thee--The increase of Abraham's seed is virtually an increase of himself. The argument here refers to Abraham himself as an example; therefore Paul quotes Genesis 22:17, "thee," instead of "thy seed."
*More commentary available at chapter level.