Midrash su Esodo 5:4

To what was Israel comparable?¹³Tanh., Exod. 5:4; Exod. R. 26:2; PRK, ibid. To one who rode on his father's shoulders. When he saw something he wanted and told his father to buy it for him, he bought it for him. <Again he did> so a second time, then a third time. As they were walking along, he saw a certain person to whom he said: Have you seen my father? [<His father> said to him: You ride on my shoulders, and whatever you desire I do for you. Now you say to him: Have you seen my father?] What did he do? He threw him off his shoulders. Then a dog came and bit him. So in the case of Israel, when Israel came forth from Egypt, he immediately enveloped them with clouds of glory. <When> they desired, the Holy One brought down manna for them. <When> they desired, he brought quail for them. Thus it is stated (in Ps. 78:29, cont.): SO HE BROUGHT THEM WHAT THEY CRAVED. He gave them everything they needed. They began to reflect and say (in Exod. 17:7): IS THE LORD PRESENT AMONG US OR NOT? The Holy One said to them: By your life, I am informing you. Behold, the dog is coming and biting you. And who is this <dog>? This is Amalek, as stated (in Exod. 17:8): THEN AMALEK CAME.

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.”