John 18:37

Art thou a king then?--There was no sarcasm or disdain in this question (as THOLUCK, ALFORD, and others, allege), else our Lord's answer would have been different. Putting emphasis upon "thou," his question betrays a mixture of surprise and uneasiness, partly at the possibility of there being, after all, something dangerous under the claim, and partly from a certain awe which our Lord's demeanor probably struck into him. Thou sayest that I am a king--It is even so. To this end was I--"have I been." born and for this cause came I--am I come. into the world, that I may bear witness to the truth--His birth expresses His manhood; His coming into the world, His existence before assuming humanity: The truth, then, here affirmed, though Pilate would catch little of it, was that His Incarnation was expressly in order to the assumption of Royalty in our nature. Yet, instead of saying, He came to be a King, which is His meaning, He says He came to testify to the truth. Why this? Because, in such circumstances it required a noble courage not to flinch from His royal claims; and our Lord, conscious that He was putting forth that courage, gives a turn to His confession expressive of it. It is to this that Paul alludes, in those remarkable words to Timothy: "I charge thee before God, who quickeneth all things, and before Christ Jesus, who, in the presence of Pontius Pilate, witnessed the good confession" (Ti1 6:13).

— Jamieson-Fausset-Brown Commentary (public domain)