One of the halachos of arei miklat is that there needs to be three arei miklat in הירדן עבר and three in Eretz Yisrael. The three in עבר הירדן only begin to function as arei miklat when the corresponding three in Eretz Yisrael are established (see Rashi, this week's parashah 4:41).
What is the reason for this halachah? Why can't the arei miklat in ever HaYarden function immediately?
The Meshech Chachmah (Maasay) explains that if the three arei miklat in הירדן עבר functioned on their own, it would leave the people living in those arei miklat without hope for freedom, and we can't leave a person without hope.
The explanation is as follows: When someone kills by accident, he must go to arei miklat. These cities are like a prison; the killer goes there for atonement (and protection). But he can hope to go free. He doesn't despair because he knows that when the kohen gadol dies, he will leave the arei miklat (see Bamidbar 35:25), and the kohen gadol can die any day.
The problem was that Elazar was the kohen gadol, and Hashem indicated that Elazar would live another fourteen years until the land of Eretz Yisrael was conquered and divided. (Hashem said that Elazer, the kohen gadol, will help divide the land [see Bamidbar 34:17]. This indicates that he will live at least until then.)
So, if the three cities in Ever HaYardan were immediately active arei miklat, the murderers living there wouldn't have any hope for freedom for another fourteen years, and we can't allow people to live without hope of immediate freedom. A person always needs hope. Only after the land is conquered and divided, and three arei miklat are established in Eretz Yisrael, will the three in הירדן עבר begin to function.
The parashah begins with the words, ההיא בעת 'ה אל ואתחנן, "And I davened to Hashem at that time." The Baal HaTurim explains that Moshe was saying, עלי ירחם אולי ישראל את חזקתי, "I gave chizuk to Bnei Yisrael. Perhaps [in this merit] Hashem will have compassion on me [and answer my tefillos]."
7. It states (Yeshayah 1:1) אמוץ בן ישעיהו חזון. The Rebbe of Zutchkeh zt'l said that ישעיהו חזון can be translated as "To see your salvation." The advice is אמוץ בן, be strong. Don't lose hope, and you will have your salvation. Therefore, it is a great mitzvah to raise people's spirits and help them have hope. In addition to the good feelings this generates, hope has the potential to lead them to their salvation.
The Baal HaTurim refers to the pesukim that precede Parashas Va'Eschanan. Moshe said (Devarim 3:21-22), 'ה עשה אשר כל את הראת עיניך אשר הממלכות לכל 'ה יעשה כן האלה המלכים לשני אלקיכם לכם הנלחם הוא אלקיכם 'ה כי תיראום לא ,שמה עבר אתה, "Your eyes have seen everything Hashem did to these two kings [Sichon and Og]; so will Hashem do to all the kings where you cross over [to Eretz Canaan]. Don't be afraid. Hashem shall wage war for you." Moshe encouraged and gave hope to the Jewish nation, and in that merit, Moshe davened ואתחנן, that Hashem should have mercy on him, answer his tefillos, and permit him to enter Eretz Yisrael.
Moshe Rabbeinu's merits are countless. He brought the Torah down to the Jewish nation, he saved the nation many times with his tefillos, and he led them out of Mitzrayim and through the desert for forty years. Who can compare to Moshe? Who can count his tefillos? Yet, he didn't ask Hashem to answer his prayers because of these merits. He requested that Hashem answer his tefillos in the merit of giving hope to the Jewish nation.
Hope is inherent in mankind. No matter what people go through, they hope for a better future. Even during the darkest moments, there is always, at the very least, a flicker of hope in their hearts. This is undoubtedly Hashem's kindness because a person could have been created always expecting the worst.
Nevertheless, despite our tendency to think positively, we worry a lot. People are frightened, "What will be if the future isn't better? What will be if I don't find a shidduch/ parnassah/health, etc.?" Therefore, it is a great mitzvah to encourage others.
