“Rabbi Yochanan said, ‘Why are Israel compared to an olive tree? It is to tell you that as the olive oozes its oil only by grinding, so Israel are reformed only by suffering’” (Minchot 53b).
Concerning the suffering that reforms a person, first one must know the meaning of being reformed. It is known that “The inclination of a man’s heart is evil from his youth.” This means that by nature, man cares only for his own sake. Naturally, it is impossible that he will be able to observe Torah and Mitzvot [commandments] for the sake of the Creator and not for his own sake.
However, through suffering, when he does not feel a good taste in corporeal things, meaning when they do not give him satisfaction in his life, since man was created with the aim to do good to His creations, he does not receive sufficient pleasure that will make it worthwhile to live in the world and tolerate everything in order to obtain the little pleasure that corporeality gives him.
To the extent that one feels torments in his life, when he has nothing from which to receive vitality, he is necessarily cancelled into working in the manner of bestowal. In other words, when he sees that he will not obtain vitality through acts of reception, he begins to perform acts of bestowal so that the acts of bestowal will give him pleasure.
It follows that the suffering reforms him, meaning the suffering he feels when he has nothing from which to derive pleasure makes him become reformed, meaning perform acts of bestowal, since “being reformed” means bestowal, as it is written, “My heart overflows with a good thing, I say, ‘My work is for the King,’” meaning to bestow.
It follows that through the suffering he suffers from having no vitality, he chooses for himself a new way and begins to engage in bestowal.
Although this, too, is with the aim to receive, it is called Lo Lishma [not for Her sake] that is close to Lishma [for Her sake]. This is the meaning of “From Lo Lishma we come to Lishma,” since “the light in it reforms him.” Since he acts in order to bestow, by this he begins to feel light in the acts of bestowal, and that light can then make him bestow.