Rashi on Numbers 7:2/רש"י על במדבר ז׳:ב׳

1הם נשיאי המטת THESE ARE THE LEADERS OF THE TRIBES — They were the officers [appointed] over them in Egypt, and they were beaten on account of them, as it says (Exodus 5:14),“The officers of the children of Israel were beaten” (Sifrei Bamidbar 45).

2הם העמדים על הפקדים THEY WHO STOOD OVER THE COUNTING — They stood with Moses and Aaron when they counted the Israelites, as it says,“With you [Moses and Aaron] there shall be [a man from each tribe]” (Numbers 1:4).