Adam Clarke's Commentary on the Bible - Genesis 18:14
Is any thing too hard for the Lord? - דבר מיהוה היפלא hayippale meihovah dabar , shall a word (or thing) be wonderful from the Lord? i.e., Can any thing be too great a miracle for him to effect? The Septuagint translate the passage, Μη αδυνατησει παρα τῳ Θεῳ ῥημα ; which St. Luke adopts almost literatim , only making it an affirmative position instead of a question: Ουκ αδυνατησει παρα τῳ Θεῳ παν ῥημα , which we translate, "With God nothing shall be impossible," Luke 1:37 .... read more
Adam Clarke's Commentary on the Bible - Genesis 18:13
And the Lord (Jehovah) said, etc. - So it appears that one of those three persons was Jehovah, and as this name is never given to any created being, consequently the ever-blessed God is intended; and as he was never seen in any bodily shape, consequently the great Angel of the covenant, Jesus Christ, must be meant. See note on Genesis 16:7 . read more