Mark 7:17

‘And when he had entered into the house from the crowd his disciples asked of him the saying.'

It was quite understandable that the disciples should want His enigmatic statement to be expanded on. They wanted to learn, and never more so than now when they had a responsibility to go out preaching. So they asked Him what His illustration meant. The gentle rebuke of Mark 7:18 confirms that they really did ask this question. No one would later have invented this about the honoured Apostles.