אבות ה׳:י״ב - ה׳:י״ג

Quick to understand and quick to forget -- his gain is canceled by his loss: As since he forgets what he learns, what benefit is there in that which he is quick to understand? It comes out that his loss is greater than his gain.

[A student who is] slow to understand and slow to forget -- his loss is canceled by his gain: As the good trait in him exceeds the negative trait; since that which he understands after the difficulty, he remembers and does not forget. And what comes out from it (the practical difference) is that if we have two students in front of us and we only have enough sustenance to [support] one of them, we prioritize the one that is slow to forget.

that is a bad portion: It would not be relevant to learn here, "pious" or "evil," as this is not something that is dependent upon the choice of a person, but rather is a disadvantage that was in him from the beginning of his creation.

There are four temperaments among givers of charity: meaning to say in the giving of charity, and not literally among givers of charity. As behold, there is among them the one who does not give. And so [too] in the adjacent [mishnah], "among those who attend the House of Study," is in the going to the House of Study.

he has an evil eye with respect to others: As it is known that [giving] charity makes one wealthy and he does not want others to get wealthy. Another explanation: There [exists] one who is concerned about the money of his relatives more than about his own money. And even though he gives, he does not want his relatives to give, so that they not lose their money. And [this explanation makes] "he has an evil eye with respect to others" similar to "he has an evil eye with respect to himself" at the end [of this part of the mishnah].