Thereupon Israel began to pour forth complaint before their Father who is in heaven, saying: “Thou hast laid many troublesome tasks upon us. Which shall we hold to and which shall we abandon? Thou hast thrown upon us great labour and great burden; Thou hast said to us, ‘Build Me a house, and although ye build, yet study the Law.’” This is the plea of His children.
Israel's Plea Under the Burden of the Commandments
Heikhalot Rabbati 29:1