This verse is sometimes interpreted to mean Jesus said it’s okay to eat animals that God’s law had declared unclean. However, a quick look at the verse in various translations reveals that Bible translators don’t all agree on how to convey the thought in English.

For example, in the Greek Interlinear, the last part of Mark 7:19 looks like, “into the sewer goes out purifying all the food.”

The King James and International Standard Versions more closely reflect the literal rendering.

“Because it entereth not into his heart, but into the belly, and goeth out into the draught, purging all meats?” (Mark 7:19 KJV)

“Because it doesn’t go into his heart but into his stomach, and then into the sewer, thereby expelling all foods.” (Mark 7:19 ISV)

Purging and expelling into the sewer paint a different meaning than declaring unclean foods clean.

Theologian Tim Hegg has a 2005 paper that goes pretty deep into the Greek grammar of this verse. Here’s his summary from page 5.

“In the final analysis, even though the best reading of the text is kaqarivzwn (masculine singular nominative), it can be understood as essentially the same in meaning as the inferior reading kaqarivzon. Grammatically, it is perfectly warranted to translate Mark 7:18–19 as follows: 18 And He said to them, “Are you so lacking in understanding also? Do you not understand that whatever goes into the man from outside cannot defile him, 19 because it does not go into his heart, but into his stomach, and goes out into the latrine, cleansing all foods (from the body)?”

It is not necessary to translate this as, “Thus he declared all foods clean”. In broader context, if Jesus was saying it’s now okay to eat rats and vultures then we would be forced to contend with numerous contradictions. Please see my notes on Matthew 15:11.