After presenting B'nei Yisroel with an admonition about the future exile, which would be followed by teshuva and geula (repentance and redemption), Moshe Rabbeinu appears to unexpectedly halt his monologue and radically "switch gears", as we read: "Then Moshe designated three cities (of refuge) on the east side of the Yarden (Jordan River), for an unwitting killer to flee..." (Devarim 4:41-42) Following Moshe's designation of these Arei Miklat (Cities of Refuge), he resumes his monologue about heeding Hashem's mitzvos.

Why does Moshe suddenly designate Arei Miklat at a juncture which seems to be totally unrelated to the context, smack in the middle of his messages of admonishment and inspiration? This question appears to have bothered the Commentators (v. Rashi, Ramban, Ibn Ezra and S'forno); I'd like to suggest an alternative approach.

Parshas Va'eschanan is unique in that its tochacha (admonition) contains the concept of teshuva. Whereas previous admonitions warned about the consequences of sin, the tochacha of Va'eschanan introduces teshuva as the key to reverse these consequences.

Teshuva is a very difficult concept for the human mind to process and accept, for teshuva precipitates atonement and can even erase sin, defying our sense of logic.

This is precisely why Moshe designated Arei Miklat in the course of delivering his admonition. Killing another person is among the most severe sins in the Torah, and it is surely irreversible. For this very reason did Moshe elect to designate Arei Miklat during his tochacha, in order to illustrate the potency of teshuva; for the unwitting killer, who committed a severe, irreversible sin, is granted atonement upon the completion of his term in Arei Miklat (v. Rambam - Hil. Rotze'ach 7:14), powerfully demonstrative of the great and challenging concept of teshuva.

If one who unwittingly takes a human life can obtain atonement for his deed, all the more so should we be inspired to engage in teshuva with the confidence that its transformative qualities can enable us to change our spiritual path and direction for the better.