שופטים, פרק ג׳, פסוק י״א

Following a military victory, the land enters a prolonged era of deep stability and calm. This quiet period represents a state of total rest and a complete break from the exhaustion of war [מצודת ציון]. The era of tranquility ultimately draws to a close with the passing of the nation's leader.

When calculating the timeline of this forty-year period, there is a broad consensus that it does not consist solely of uninterrupted peace. Instead, the forty years encompass the entire historical chapter, beginning from the very start of the nation's subjugation to a foreign power and concluding at the end of their days of rest [מצודת דוד, רלב״ג].

Beyond the historical timeline, this specific duration of peace carries a profound spiritual meaning. The forty years of calm were granted as a direct reward for the dedicated Torah study of Othniel the son of Kenaz. Through his deep analysis and learning, he successfully recovered laws that the Israelites had forgotten. Because these original laws were given to Moses over a period of forty days, the land was correspondingly rewarded with forty years of peaceful rest [חומת אנך].