John 5:33 - Ellicott's Commentary On The Whole Bible

Ye sent... — Both verbs are perfects. Better, therefore, Ye have sent; He hath borne witness. The pronoun “ye” is emphatically opposed to the “I” of the following verse. They sought human witness. He had witness which was divine. The object of John’s mission was to bear witness of the Light (John 1:7), and this he did to them (John 1:19 et seq.)