The Context

As Moshe prepared to address the Jewish people towards the end of his life, he told the Levites to gather the people so he could speak to them. “Assemble to me all the elders of your tribes and your officers, and I will speak these words into their ears, and I will call upon the heaven and the earth as witnesses against them.” (Devarim 31:28)

Normally, the kohanim would blow trumpets to gather the assembly. However, the verse implies that on this occasion, they did not use the trumpets, as the Levites were tasked with gathering the people.

Rashi explains that this was because God had instructed Moshe to make the trumpets for himself, and their use was closely associated with Moshe's leadership.