Verily, verily, I say unto thee, We speak that we do know, and testify that we have seen; and ye receive not our witness.
Verily, verily, I say unto thee, We speak that we do know, and testify that we have seen - that is, by absolute knowledge and immediate vision of God, which "the Only begotten Son in the bosom of the Father" claims as exclusively His own (John 1:18).
And ye receive not our witness - referring to the class to which Nicodemus belonged, but from which he was now beginning to be separated. Though our Lord says, "we speak" and "our testimony," Himself only is intended-probably in emphatic contrast with the opening words of Nicodemus, "Rabbi, we know," etc.