Rabbi Sacks comments on the fact that Moses implies the people will leave for 3 days to worship Adonai, when in fact the intention is to leave entirely. He recalls Jacob, who left Laban behind his back, and made an excuse not to travel together with Esau later on. Jacob was also misleading in the situation with the Shechemites when he proposed circumcision. Abraham and Isaac pretended their wives were sisters when leaving home because of famine. This type of deception is a pattern in the Tanakh.
