Musar על יבמות 242:13

And expounding on "it is very stormy round about Him" (Ps. 50:3) - "this teaches that the Holy One blessed be He scrutinizes judgment on His pious ones to the degree of a hair's breadth" (Yevamos 121a).

Those who ask this question do not really display much wisdom. The very quality that enabled Isaac to be judged by the attribute of Justice is what secures Israel's eventual lofty status, its joining the ranks of בני עליון, superior beings. First we must examine the meaning of the מדרשים, Bereshit Rabbah 12,15 et al., which report G–d as having wanted to create a universe that would be administered solely by the attribute of Justice. These Midrashim report that when G–d realized that such a universe could not endure for long, He co-opted the attribute of Mercy. I have dealt with this problem at length on page 14 of this volume, where I also explained that one must not conceive of G–d as having "changed His mind," having abandoned a previous plan, seeing לא בן אדם ויתנחם, "He is not human that He should have regrets" (Numbers 23,9). All that happened to G–d's original plan is that instead of the yardstick of the attribute of Justice being applied universally, it is applied only to בני עליה, the truly righteous. To them G–d applies the most stringent yardstick. It is the application to them of the undiluted attribute of Justice which stamps them as superior creatures, בני עליה. They are but few in numbers. G–d applies a mixture of the attributes of Justice and Mercy to the vast majority of people. In the future under discussion, however, when everybody will qualify as a member of that formerly select group, everybody will be judged by the undiluted attribute of Justice and will prevail even under such scrutiny. It is impossible for people nowadays to qualify for such a status until after their bodies, i.e. the raw-material their bodies are made of, have undergone a process of refinement such as the experience of exile and other afflictions. The more of such suffering the Jewish people experiences, the greater the evidence that G–d has decided to become very exacting with us in order to prepare us for that idyllic state. When viewed under this perspective, we understand that the application of the attribute of Justice is really an expression of the greatest love, חסד, of G–d for the Jewish people.