The Jews (as we are told) used to call God The Father, in a way of eminency: they understood that he spake to them of his Father; but they would not understand when he spake to them of his Father, or the Father, he meant God the Father of all; their minds were blinded, that they could not see, and their hearts hardened, that they could not understand.
Related Commentaries of John 8:27
John 8:27
27 They understood not that he spake to them of the Father.