en_tn/num/10/03.md

in front of you

"while you are present." This means that Moses was to be there with the priest when he blew the trumpets.

the leaders, the heads of the clans of Israel

These two phrases refer to the same group of people. Here the second phrase is used to describe the first phrase. AT: "the leaders, who are the heads of the clans of Israel" (See: rc://en/ta/man/translate/figs-parallelism)

When you blow a loud signal

Here the word "you" is plural. Yahweh is speaking to Moses, but he his referring to the priests. The priests will blow the trumpets, Moses will not. AT: "When they blow a loud signal" (See: rc://en/ta/man/translate/figs-you and rc://en/ta/man/translate/figs-metonymy)