In Parshas לך לך Rashi explains, the word לך, "to you" implies
that it's for your own benefit.
In this week's Parsha it says שלח לך Here too לך should imply
that it's for your own (Moishe) benefit.
R. Chaim Vital writes, that because of the מרגלים Moishe's life
was extended an additional 40 years.
Had the בני ישראל entered ארץ ישראל immediately then Moishe
would have had to die before entering ארץ ישראל.