Joseph fell on his brother Benjamin's neck and wept, and Benjamin wept on his [Joseph's] neck.
Genesis 45:14
Rashi comments: "Joseph foresaw prophetically that the first two Temples, destined to be built in Benjamin's territory would be destroyed. Benjamin wept on his neck, for he in turn foresaw prophetically that the Tabernacle of Shiloh, destined to be in Joseph's territory, would also be destroyed."
Why did Joseph and Benjamin cry over the destruction that would occur in each other's territories, but not over the destruction that would occur in their own territory?
The function of crying, generally, is to alleviate pain caused by a distressing situation, it does not actually ameliorate the situation. Thus, as long as we can remedy a distressing situation, we should try to do so instead of comforting ourselves with tears.
Consequently, in regard to the Tabernacle that would be destroyed in his own territory, Joseph had to focus on doing everything he could to forestall its destruction. Crying about it would have been counterproductive. He was ultimately powerless to stop the destruction that would occur in Benjamin's domain, however, since the destiny of Benjamin's territory was in Benjamin's hands. Thus, after Joseph did everything he could on behalf of Benjamin and still saw that the Temples would be destroyed, he felt so bad about it that he burst into tears. Likewise, Benjamin cried over the destruction that would occur in Joseph's territory, not for the destruction that would occur in his own.
In our lives, when we see that our fellow's "temples" are being destroyed, i.e., that they are failing to sanctify their personal lives and spheres of influence, we must help them by advising them gently and praying on their behalf. But ultimately, they control their own destiny by their freely made choices. At some point, our concern for them can express itself in tears.
But when we see that our own "temple" lies in ruins, we do not have the luxury of comforting ourselves with crying. In fact, crying may impede our work, since we may be tempted to feel that we have fulfilled our moral obligation by the mere fact that we care, even if we do not act on our concern
—From the Kehot Chumash