Why will you vomit out the bread that you ate?
Rashi: Due to shame.
R. Yonah: When you eat with him, you see that his face is not pleasant and his heart is not with you. You eat your bread in sadness, and the stomach does not grind it properly. Therefore, you will vomit it out.
What do we learn from "v'Shiches Devarecha ha'Ne'imim"?
Rashi: You spoke nice words to him - you lost everything.
R. Yonah: If you are a Chacham in Torah, or in any Chachmah or Derech Eretz, and you speak Divrei Da'as and Chachmah on your table, you will ruin your nice words. They will be a burden to him, for his heart is sad that you eat with him. It was said, do not speak with one whose shoe is narrow 1 .
Malbim: This shows that the verse gave a Mashal, for food of the Nefesh is learning concepts. One must be careful not to learn from one who is stingy. Stinginess and generosity apply to all judgments of intellect, which judges for good or bad. Vision borders against the power of intellect, which understands things that Binah cannot attain, including the laws of Chachmah and secrets of Hashem hidden from all creations. An expression of Sechel is used for them, e.g. "u'Lehaskil ba'Amitecha" (Daniel 9:13), and not an expression of Binah 2 .
I.e. he is in pain. (PF)
Malbim: All people are the same regarding Binah. One who argues, this is imagination and Sheker. What is out of Binah, e.g. the ways of Chachmah and supreme Yedi'os, there can be many ways to understand them. A Chacham understands in the way of Chachmah, and a fool in the way of folly. A generous person judges according to Chachmah, and a stingy person in the way of folly, e.g. not to give from his bread to the poor.