We begin this Shabbat the Book of Devarim, also known as משנה תורה. Unlike the other four books of the Torah, דברים is spoken entirely by משה רבינו during the last thirty-seven days of his life.
Rashi points out that Moshe learned from Yakov Avinu that the most appropriate time for תוכחה, rebuke, is at the end of one’s life. Yehoshua, Shmuel, and David, all gave תוכחה before their deaths.
The reason Rashi gives for this is that the timing for rebuke is everything. Yakov Avinu was afraid that had he rebuked Reuven earlier, he may have become angry. He could have attached himself to Eisav.
Words spoken before one’s death leaves a lasting impression. The parting advice of a parent remains with an individual forever.
Moshe’s parting words to בני ישראל have remained with us for all of time.