출애굽기 5:4 미드라쉬: Midrash Tanchuma Buber, Shemot Rabbah & Midrash Tanchuma

R. Judah the Levite said: The tribe of Levi was exempt from the public service.²⁷Gk.: leitourgia. Pharaoh said to them: Because you are exempt, you come and say (in Exod. 5:3): LET US GO…, AND LET US SACRIFICE.²⁸Tanh., Exod. 2:6; Exod. R. 5:16. He said to them (in vs. 4): WHY DO YOU, MOSES AND AARON, DISTRACT THE PEOPLE FROM THEIR TASKS? What is the meaning of WHY (LMH)? You are nothing (LMH),²⁹LMH, voweled as lamah means “nothing.” It comes from the Aramaic, la’ ma, which literally means “no what,” i.e., “no thing.” and your words are nothing (LMH). (Ibid., cont.:) GO TO YOUR BURDENS.

“The king of Egypt said to them: Why, Moses and Aaron, do you disturb the people from their work? Go to your burdens” (Exodus 5:4).
“The king of Egypt said to them: Why, Moses and Aaron” – what is why [lama]?²⁹The question is difficult. Moses and Aaron had already explained why they were disturbing the people from their work. The midrash interprets the word lama as lema. Not “why” but rather, “what” are you and what are your words worth? He said to them: ‘What are you, and what are these matters?’
“Go to your burdens” – Rabbi Yehoshua ben Levi said: The tribe of Levi was unencumbered with the backbreaking labor. Pharaoh said to them: ‘Because you are unencumbered you say: “Let us go and sacrifice to our God” (Exodus 5:8); “go to your burdens.”’

And the king of Egypt said unto them: For what reason do you Moses and Aaron cause the people to break loose from their work? (ibid., v. 4). What is the meaning of lamah (“for what reason”)? He said to them: “For what (lamah) do you think you are? And for what purpose (lamah) are your words?” As though to say to them: “Enough! Get you unto your burdens.”