Paul’s Isaiah quotation in Gal 4 is ground well worked. Another scholarly contribution is warranted, however, because aspects of Isaianic research over the past several decades, research largely unexamined within Pauline scholarship, may shed light on Paul’s deployment of Isa 54:1 within his allegorical appeal to the Sarah/Hagar narrative. Moreover, Paul’s larger “offspring” theology within Gal 3 and 4 may find its substantial location within the broader cross-currents of Isaiah’s theologizing on the self-same subject matter. In particular, the identification of the “servants” of the Lord as a theme, if not the major theme, of Isaiah 54–66 opens up a dialogical conversation between Isaiah and Paul concerning a theological problem they both share, namely, “Who are the true offspring of Abraham/Zion?” Isaiah recalibrates Abraham’s promised offspring via the emerging figure of the servant of the Lord in the redemptive dynamic of Isa 40–53, and this recalibration leans into the unfolding of the servants as the progeny of the servant’s work. In summary, within an Isaianic frame, Abraham’s offspring are the servant’s offspring.
