A.T. Robertson Commentary John 18:21

"Why askest thou me? Ask them that have heard [me], what I spake unto them: behold, these know the things which I said." — John 18:21 (ASV)

Ask them that have heard me (ερωτησον τους ακηκοοτας). First aorist (tense of urgent and instant action) active imperative of ερωταω and the articular perfect active participle accusative masculine plural of ακουω, to hear. There were abundant witnesses to be had. Multitudes had heard Jesus in the great debate in the temple on Tuesday of this very week when the Sanhedrin were routed to the joy of the common people who heard Jesus gladly . They still know.