This is the occasion Christ called the multitudes around Him to make a momentous statement of principle. It was a matter on which Israel’s ‘clergy’ had misled them – what defiles people to keep them out of Heaven? Here is the Lord’s answer, and the only remedy.
Sin and guilt do not come, says Christ, from eating ritually banned foods, but are generated from the thoughts of the mind – the ‘heart’. These contaminate us, shutting us off from God and Heaven. Here is the Lord’s list of our sins, and His remedy for a new life.