Amid the later books of the Bible’s prophecies of destruction and accounts of divine retribution, the book of Ruth stands out. The midrash in Ruth Rabbah (2:14) states: “This megillah has no laws of purity or impurity, no transgressions and no mitzvot. So why was it written? It is just to teach how much reward comes to those who act with loving-kindness (chesed).”
In the context of the Bible, Ruth is unusually sweet. Sin, if present at all, remains in the background. Its characters must choose between the merely permissible and the exceptionally virtuous.