Why askest thou me? — Comp. John 5:31. The pronoun “Me” is not the emphatic word as it is generally taken to be. The stress is on the interrogative, “Why, for what purpose, dost thou ask Me? If you want witnesses, ask them which heard Me.”
Behold, they know what I said. — Better, behold, these know what I said. He pointed probably to some who were then present. In the next verse there is a reference to the “officers” who, as we know from John 7:32; John 7:46, had heard this doctrine.