27 For it is written:
"Rejoice, barren one, who does not give birth;
break forth and shout, you who have no labor pains;
because the abandoned woman has many more children
than she who has the husband."The quote is from Isaiah 54:1—in that chapter Jehovah is telling Israel, His abandoned ‘wife’, that He is going to take her back, restore her, and her future felicity will make her forget the pain of rejection. However, that restoration will presumably be based on the new covenant (Jeremiah 31), as is Christ’s Gospel.
28 Now we,Perhaps 8% of the Greek manuscripts read ‘you’ for "we" (as in NIV, NASB, LB, TEV, etc.). brothers, like Isaac, are children of promise. 29 But, it is the same now as it was then: the one born according to flesh persecutes the one born according to Spirit.