Kommentar zu Dewarim 3:28

וצו את יהושע AND GIVE JOSHUA CHARGE regarding the cumbrance, the burdens and strifes that he will have to bear (cf. Deuteronomy 1:12).

וצו את יהושע, "and command Joshua, etc." What precisely was Moses to command Joshua? Yalkut Shimoni item 823 quoting Sifri on Pinchas claims that Moses was to command Joshua not to be taken in by the Gibeonites. Another opinion cited claims that Moses warned Joshua concerning possible strife amongst the people. There is no hint in the text of this and unless it is based on tradition we do not have to accept this explanation. I believe that the plain meaning of the verse may be understood in light of Samuel I 13,14: ויצוהו ה׳ לנגיד על עמו, "the Lord appointed him as ruler over His people." The word means "he appointed." Please refer to what I have written on Exodus 6,13 ויצום אל בני ישראל. Moses simply told Joshua to exert authority over Israel already while he was still alive. He personally would support him in this before the eyes of the whole nation.

Regarding the troubles, the burdens, etc. As the verse says (above 1:12), “Your troublesomeness, your burdensomeness, and your contentiousness.” For if וצו (command) is referring to אמצהו וחזקהו (embolden him and encourage him), then וחזקהו would not be preceded by a vov (and), which implies that besides the command given to Yehoshua, you are also to encourage him and embolden him. We see from this that the command is one matter, and “encourage him and embolden him,” is a separate matter.