“Rabbi Yehoshua Ben Levi said, ‘Anyone who delights the selfish breaks a commandment not to do, as was said, ‘Do not eat the bread of an evil-eyed man,’ for as he assumes so it is, he will tell you ‘Eat and drink’ but his heart is not with him’” (Sotah 38b).
We should understand this, for it seems as though if his friend invites him for a meal, why should he care? After all, there is a rule that in several places it is said, “He is forced,” and then his heart is certainly not with him, but it is said that his heart is really fine.
Therefore, here, when he invites him verbally, why is he forbidden to eat at his place, to the point that it says that he breaks a commandment not to do, and Rav Nachman Rav Yitzhak says that he breaks two commandments not to do?
But according to the rule that one must achieve the degree of receiving in order to bestow, meaning to receive all the pleasures only in order to bestow upon the Creator, one who eats at another’s place and knows that this brings contentment to the host, this follows the purpose of creation that man should achieve wholeness.
But one who eats and the aim cannot be to please the host, since the host does not enjoy his eating because the host is evil-eyed, this is against the goal. Therefore, it is forbidden to eat.