“For as a man thinks in his heart, so is he.”  I’ve heard this quoted many times to make the point that you are what you think.  Or shall I say misquoted?  That’s not what the text actually says, nor what it means.  Here’s the passage in context, in three different translations:

Do not eat the bread of a selfish man, or desire his delicacies; For as he thinks within himself, so he is.  He says to you, “Eat and drink!” But his heart is not with you. You will vomit up the morsel you have eaten, and waste your compliments. (Prov 23:6-8, NASB)

Do not eat the food of a begrudging host, do not crave his delicacies; for he is the kind of person who is always thinking about the cost.  “Eat and drink,” he says to you, but his heart is not with you. 8 You will vomit up the little you have eaten and will have wasted your compliments. (Prov 23:6-8, NIV)

Do not eat the bread of a man who is stingy; do not desire his delicacies, for he is like one who is inwardly calculating. “Eat and drink!” he says to you, but his heart is not with you. 8 You will vomit up the morsels that you have eaten, and waste your pleasant words. (Prov 23:6-8, ESV

The first thing to notice in all three translations is that it doesn’t read “a man” as in any person (as one might infer from the KJV), but rather “he.”  It has a specific kind of person in mind.  What kind of person is that?  A stingy person.  Solomon is warning against duplicitous, selfish people who have their own interests in mind, but act as if they care about you.  They are not showing you their true hand.  Their heart doesn’t match their words.  Outwardly they pretend to be generous, but inwardly are stingy.

While one may be what they think (or conversely, think according to what they are), that’s not the point of Proverbs 23:7.

Keep it in context….