‘Jesus says to them, “If you were Abraham's children you would do the works of Abraham. But now you seek to kill me, a man who has told you the truth that I have heard from God. This is not what Abraham did”.'
Jesus now explained that if they were really Abraham's children they would behave as Abraham behaved. But the very fact that they were plotting His death proved that they were not doing so. He had come as a man who had told them the truth which He had heard from God and yet they were seeking to kill Him. Abraham, in contrast, welcomed the messengers that came from God (Genesis 18:2 etc.). Thus they were not behaving like Abraham.