For this is the word of promise
The following passage is the Scripture, which contains the promise concerning the birth of Isaac; which was the produce, not of nature, but of divine grace and power; and was typical of the regeneration of God's elect, who "as Isaac was, are the children of promise", ( Galatians 4:28 ) , for as Ishmael was a type of them that are born after the flesh, and are carnal men, so Isaac was a type of those, who are born after the Spirit, and are spiritual men: the promise is,
at this time will I come, and Sarah shall have a son;
the passage referred to is in ( Genesis 18:10 ) ; which there stands thus, "I will certainly return unto thee, according to the time of life, and lo, Sarah thy wife shall have a son": some difference there is between the words as cited by the apostle, and as they stand in the original text; the word "lo", is omitted by the apostle, nor was there any necessity to repeat it, since it was used only to excite Abraham's faith, attention, and wonder; also the phrase "thy wife", is neglected, the reason is, because the words in Genesis are an address to Abraham, here the substance of the promise to him is produced; besides it was not only well known in the apostle's time, that Sarah was the wife of Abraham, but that as such she brought forth Isaac, wherefore it was not so very necessary it should be mentioned here; add to this, that it is not repeated in ( Genesis 18:14 ) , which will justify our apostle in the omission of it: but the greater seeming difference is, that what in Genesis is rendered, "according to the time of life", is by the apostle, "at this time": some think, that there may be an emendation of the present original text, and suppose a various reading, and that the apostle, instead of (hyx) , "life", read (hzx) , "this", but there is no occasion for such a supposition, or to make this amendment: for the phrase "the time of life", signifies the present time, the "nunc stans"; so R. Levi ben Gerson F6, understands this phrase, "according to the time of life", (hte tdmwew tmyyq ayhv tazh tek) , "according to this time which is now standing and abiding" and adds, rightly is this said, because neither time past nor to come are to be found, only the present time, the "nunc stans" and afterwards more than once explains it, of this present time, the next year: and so both R. Solomon Jarchi, and R. Aben Ezra F7, expound it, (tazh tek) , "according to this time", the year following; that is, exactly according to this present time next year, or this time twelve month; besides, in ( Genesis 17:21 ) it is said, "at this set time", and in ( Genesis 18:14 ) , "at the appointed time"; all which support the apostle in his version.
F6 Perush in Gen. fol. 26. 4. & 27. 2, 3. Vid. in 2 Reg. iv. 16.
F7 In Gen. xviii. 10.