First Act, then Order

And you shall command the Children of Israel that they take for you pure olive oil, pressed, for lighting, to make a light shine out continuously. Exodus 27:20

It is of note that the in previous parasha, Moses was instructed by God no fewer than twenty-nine times “v’asita” (“you shall make”). 

My father noted that the lesson is that a leader’s primary job is to do, not to give orders to others. Only after Moses had acted, did he have the right to command others.