The question in Mark 7:19 is whether the final phrase of the verse is part of Jesus’ original sentence, or whether it is a comment by the author of the Gospel, drawing a conclusion from what Jesus said.
View 1 – Jesus said it:
The King James Version takes the conclusion as being part of Jesus’ sentence.
“Because it entereth not into his heart, but into the belly, and goeth out into the draught, purging all meats?” (KJV)
The word ‘the draught’ here means ‘the latrine’. Although the context makes this clear, the verse uses a Greek term ‘aphedron‘ which was unknown until an inscription was unearthed by archaeologists excavating a public latrine in Pergamon in 1902. The only real problem with this reading is how exactly entering into the toilet would cleanse the meat?
View 2 – Mark said it:
Most modern versions take the view that the comment is by Mark, and often add brackets to indicate this.
“For it doesn’t go into their heart but into their stomach, and then out of the body.” (In saying this, Jesus declared all foods clean.) (NIV)
Although as Mark’s words are not normally bracketed, this could mislead some readers into thinking there is a question on whether the words are genuine. But there is not, the words are there in all manuscripts.
All things being possible on the Internet you will occasionally encounter food-law keeping Sabbatarians and Messianics who claim that it’s a late scribal insertion, but in textual terms it’s akin to those folk who deny the moon landings. If pressed they will usually reveal that they don’t accept the authority of Mark or Paul anyway.
Little ‘o’ or big ‘O’?
As above all Greek manuscripts have these words but there is a very small difference between the ‘majority text’ (the large numbers of later manuscripts followed by the King James Version) which has an omicron in the verb ending “cleansing [καθαρίζον] all meats”, and the ‘minority text’ (the smaller number of older manuscripts followed by most modern versions) which instead has an omega [καθαρίζων], which lends itself to the reading that Jesus so saying “thus cleansed” all meats.
It is not just the older manuscripts which support the conclusion that this is Mark’s comment. The idea that it is Mark’s comment also fits better with the three-times repeated argument of Jesus – first outside with the crowd (15), then inside the house (19) and the restatement and conclusion (23) – that it the concern here is sin making unclean, not directly a comment on foods.
14 Again Jesus called the crowd to him and said, “Listen to me, everyone, and understand this. 15 Nothing outside a person can defile them by going into them. Rather, it is what comes out of a person that defiles them.” 17 After he had left the crowd and entered the house, his disciples asked him about this parable. 18 “Are you so dull?” he asked. “Don’t you see that nothing that enters a person from the outside can defile them? 19 For it doesn’t go into their heart but into their stomach, and then out of the body.” (In saying this, Jesus declared all foods clean.) 20 He went on: “What comes out of a person is what defiles them. 21 For it is from within, out of a person’s heart, that evil thoughts come—sexual immorality, theft, murder, 22 adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. 23 All these evils come from inside and defile a person.” (NIV)
It therefore would make more sense that Mark, writing later when the Judaizing (Paul’s word) meats controversies were doing so much damage in the church, would therefore underline the relevance of Jesus’ words, to support the position taken in the New Testament letters. Which is no different from the validity of any other verse in the Gospel.