Why askest thou me? Ask them - Jesus here insisted on his rights, and reproves the high priest for his unjust and illegal manner of extorting a confession from him. If he had done wrong, or taught erroneous and seditious doctrines, it was easy to prove it, and the course which he had a right to demand was that they should establish the charge by fair and incontrovertible evidence. We may here learn:
1. That, though Jesus was willing to be reviled and persecuted, yet he also insisted that justice should be done him.
2. He was conscious of innocence, and he had been so open in his conduct that he could appeal to the vast multitudes which had heard him as witnesses in his favor.
3. It is proper for us, when persecuted and reviled, meekly but firmly to insist on our rights, and to demand that justice shall be done us. Laws are made to protect the innocent as well as to condemn the guilty.
4. Christians, like their Saviour, should so live that they may confidently appeal to all who have known them as witnesses of the sincerity, purity, and rectitude of their lives, 1-Peter 4:13-16.

Why askest thou me?.... He seems surprised at the high priest's conduct, that he should put such questions to him, who stood bound before him; was brought there as a criminal, and was the defendant, and not obliged to accuse himself; nor could it be thought, that whatever evidence or testimony he should give, would have much weight with the persons before whom he stood.
Ask them which heard me, what I said unto them; he appeals to his hearers, many of whom were then present; and these his enemies, even his worst enemies, so clear was his case, so free was his doctrine from sedition and blasphemy, so innocent was he in the whole of his deportment and conduct, that he even submits to have his case issued and determined by what his hearers should say of him; and these not his friends, but his enemies; see Isaiah 50:8;
behold, they, or these,
know what I have said; pointing at some persons present, perhaps the very officers who had been sent to take him before, but returned without him, declaring that never man spake like him.

Why askest thou me? ask them which heard me . . . they know what I . . . said--This seems to imply that He saw the attempt to draw Him into self-crimination, and resented it by falling back upon the right of every accused party to have some charge laid against Him by competent witnesses. (Also see on Mark 14:54.)

Why askest thou me - Whom thou wilt not believe?