Tafsiran Bilangan 7:2: Rashi, Sforno, Rashbam & Siftei Chakhamim

הם 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).

הם נשיאי המטות, הם העומדים על הפקודים. Seeing they all occupied official positions the gift/offering each one brought was on behalf of his tribe and its members. Seeing each one was in charge of other people, he felt a sense of some members of his tribe being suspected of some misdemeanour. At the same time, seeing that they did not only represent the members of the tribes but were נשיאים, “princes” in their own right, they agreed to act as the interlocutors of their tribe in trying to obtain atonement for the errors committed by members of their tribe by offering a communal offering on their behalf.

הם העומדים על הפקודים. The ones who have already been mentioned by name in Numbers 1,5-16.

הם 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).