Exodus 5:17 - Ellicott's Commentary On The Whole Bible

Ye are idle. — Idleness was regarded by the Egyptians as one of the worst sins. It had to be specially disclaimed in the final judgment before Osiris (Birch, in Bunsen’s Egypt, vol. v. p. 254). Men sometimes disclaimed it in the epitaphs which they placed upon their tombs (Records of the Past, vol. vi. p. 137). Pharaoh had already made the charge, by implication, against Moses and Aaron (Exodus 5:4). No doubt, among the Egyptians themselves, a good deal of idleness resulted from the frequent attendance upon religious festivals (Herod. ii. 59-64). Hence the charge might seem plausible.