What is the attribute of mercy? Our sages defined it as: “what’s mine is yours and what’s your is yours.” And if all the people in the world were to behave that way, it would cancel all the glory of the attribute of truth and judgment, because if each and everyone would be naturally willing to give everything he has to his fellow man and take nothing of another for himself, then the whole interest in lying to one another would disappear, and there would be no room to speak of the attribute of truth whatsoever, because true and false are relative – and if there were no falsehood in the world, there would be no concept of truth. Needless to say that the other attributes that are there only to strengthen the attribute of truth because of its weakness, would also be cancelled.

Truth is defined in the words: “what’s mine is mine, and what’s yours is yours.” That contradicts the attribute of mercy and cannot altogether tolerate it because in truth, it is unjust to labor and strain for another, because besides causing his friend to fail, he accustoms him to exploit his fellow man. Thus, truth dictates that every person treasure his own assets for a time of need so he will not have to be a burden on his fellow man.

Baal HaSulam (Kabbalist Yehuda Ashlag), in “Peace in the World.”