Jesus said this while teaching in the synagogue in Capernaum.
59. He spoke these things in the synagogue. John points out the place, that we may know that there were many present, and likewise, that a sermon was delivered as on a weighty and important subject. But it immediately follows that out of so great a multitude there were scarcely to be found a very few who profited by it; and — what is worse...
When Jesus knew in himself,.... And of himself, without any intelligence from others, or hearing what was said, being the omniscient God: that his disciples murmured at it; at the doctrine he had delivered, looking upon it as absurd, incredible, and contrary to sense and reason: he said unto them, does this offend you? or trouble you? cannot you get over this? cannot you understand it? or account for it?
These things said he in the synagogue--which seems to imply that what follows took place after the congregation had broken up.