‘This, they said, tempting him.’ Or as the modern translations put it, testing him, which is quite right.
In italics in the King James Version you’ll find the words, ‘as though he heard them not.’ They are italicised because they are not in the Greek. This is a case where our translators are trying to help us out, but in this instance, they have undoubtedly made a mistake. The Lord Jesus Christ did not write on the ground ‘as though he heard them not’. It could be there is an element of truth in this, but that phrase is not actually in the original, it is just the translator trying to help us.