{Our father is Abraham} (ho pat(8872) h(886d)(936e) Abraam estin).
They saw the implication and tried to counter it by repeating
their claim in verse  33  which was true so far as physical
descent went as Jesus had admitted (verse  37 ). {If ye were}
(ei este). Strictly, "if ye are" as ye claim, a condition of
the first class assumed to be true. {Ye would do} (epoieite
an). Read by C L N and a corrector of Aleph while W omits an.
This makes a mixed condition (protasis of the first class,
apodosis of the second. See Robertson, _Grammar_, p. 1022). But B
reads poieite like the Sin. Syriac which has to be treated as
imperative (so Westcott and Hort).