John 6:61

If Christ had wished to say nothing else than that his disciples should be filled with his doctrine, that being his flesh and blood, it would not have been a hard saying; neither would it have shocked the Jews. He had already said as much in the former part of his discourse: but he goes on in still stronger terms, notwithstanding their complaints; and, as they were ignorant how he would fulfil his promise, they left him, (Calmet) and followed the example of the other unbelieving Jews, as all future sectarists have, saying: how can this be done?