The Rashi

Assemble to me—On this day they did not blow the trumpets to assemble the congregation [as they usually did (see Bamidbar. 10:2-3,7), because the verse says, “Make for yourself [two trumpets of silver...and they will be for you to call the assembly]” (Bamidbar 10:2). [Now, this was a commandment directed personally to Moshe, because “for yourself” and “for you” are both written in the singular form. Hence, Moshe made these trumpets and kept them in his possession,] and he did not give Joshua authority over them during Moshe’s lifetime. Moreover, these trumpets were hidden away [by God] even during his [Moshe’s] lifetime, prior to the day of his passing, thus affirming the words of the verse, “and there is no ruling on the day of death.”