“Thus would the clean-minded in Jerusalem do: They would not come into a meal unless they knew who was dining with them” (Sanhedrin 23a).
“Clean-minded” means people who are cleansed from reason, as our sages said, “So and so was cleansed of his possessions.” This means that they are people who go above reason, which in plural form [in Hebrew], it is called “clean-minded.” These people should be careful not to come in contact with people who can only work within reason, since the view of landlords is opposite from the view of Torah.
“The view of landlords” means within reason, when one understands what he is doing and always thinks whether it is worth his while to do or not to do, meaning what benefit the act he is doing will yield for him.
Conversely, “the view of Torah” is as our sages said, “The Torah exists only in one who puts himself to death over it” (Berachot 63b). This means that he should annul his self, meaning annul all of his existence. Thus, there is no reason here with which to think what observing Torah and Mitzvot will give him.
A landlord always thinks about property. Hence, with everything he does, he thinks what this can add to his property. But the path of Torah is annulment of property. Thus, those who study Torah and go within reason, meaning with the view of landlords, have a different way than the students of Torah who are going above reason, which is called “clean-minded,” for they are cleaned from reason because they want the cancellation of reality.
Thus, which view can be said that obligates him to completely annul himself? This discernment is called “not in order to receive reward.” Therefore, they need great care so they will not be taken after the students of Torah who are going within reason.