Paul uses this phrase to move to the next question that the Corinthians had asked him.
## food sacrificed to idols ##
The pagan worshipers would offer grain, fish, fowl, or meat, to a god. The priests would burn a portion of it on the altar. Paul speaks about the remaining portion, which would be returned to the worshiper or sold in the market.
## We know that "we all have knowledge" ##
Paul is quoting a phrase that some Corinthians used. AT: "We all know, as you yourselves like to say, that 'we all have knowledge'".
## puffs up ##
"makes one proud" or "makes one think more of themselves than they should"
## thinks he knows something ##
"believes he knows everything about something"
## that person is known by him ##
"God knows that person" (See: [[rc://en/ta/man/translate/figs-activepassive]] )