Jesus had spoken of truth, and Pilate throws the word back as a question. John does not tell us his tone, and the commentators read it differently. Barnes thinks "This question was probably asked in contempt, and hence Jesus did not answer it." He adds that if Pilate had asked sincerely, as Nicodemus once came seeking (John 3:1-2), Jesus would have explained.

Matthew Henry allows that Pilate may have spoken as a learner, as a judge, or "as a scoffer, in a jeering way." Gill also allows that it may have been said "in a scornful, jeering way." What the text does show is that Pilate did not stay for an answer.

John records no answer from Jesus, and Pilate did not wait for one: "when he had said this, he went out again unto the Jews." Gill notes, "we do not find that our Lord gave any answer to this question." Instead Pilate announced his verdict to the accusers: "I find in him no fault at all" (John 18:38).

The Gospel itself has already answered Pilate's question. Jesus had told His disciples, "I am the way, the truth, and the life" (John 14:6), and had prayed to the Father, "thy word is truth" (John 17:17). The answer to "What is truth?" was standing in front of Pilate.

Pilate kept going "out again" because the Jews would not enter the judgment hall, so as not to be defiled before the passover (John 18:28). His question in Greek is three short words, Ti estin alētheia, "What is truth?" The word alētheia means truth, what is real and not false.

The word translated "fault" is aitia, which the BibleHub interlinear glosses "fault/guilt"; the ESV renders it "guilt." Barnes explains what Pilate had concluded: he was satisfied "that he was not a king in the sense in which the Jews accused him; that he would not endanger the Roman government, and consequently that he was innocent of the charge alleged against him."

Pilate asked one of the greatest questions a person can ask, and then walked away from the only One who could fully answer it. Matthew Henry observes, "many put this question that have not patience and constancy enough to persevere in their search after truth." In his Concise Commentary he turns the question into a habit for every reader of Scripture: "When we search the Scriptures, and attend the ministry of the word, it must be with this inquiry, What is truth? and with this prayer, Lead me in thy truth; into all truth."

There is also a hard lesson here. Pilate did find one truth: Jesus was innocent ("I find in him no fault at all"). Yet he still "delivered he him therefore unto them to be crucified" (John 19:16). Seeing the truth is not the same as obeying it.