Exodus 10:24
And Pharaoh called unto Moses, and said, Go ye, serve the LORD; only let your flocks and your herds be stayed: let your little ones also go with you. And Pharaoh called unto Moses, and said, Go ye, serve the LORD; only let your flocks and your herds be stayed: let your little ones also go with you.
The offer came after three days of thick darkness over all Egypt, darkness that could be felt, in which the Egyptians saw not one another nor rose from their place, while the children of Israel had light in their dwellings. That darkness was more than loss of light, for the atmosphere became very oppressive so that breathing was difficult for the Egyptians, while the Hebrews had pure air and light in their dwellings. It challenged Egyptian worship of Isis and Osiris and showed Jehovah's supremacy as Israel's deliverer.
Frightened and compelled by the plagues, Pharaoh permitted Israel to go serve the Lord and let their little ones, children and wives, go with them, but demanded that their flocks and herds be stayed in Egypt. His offer was only a reluctant, limited concession yielded under compulsion and grievous affliction, one step in a series in which he yielded no more than the dreadful visitations of wrath forced from him. By withholding the flocks and herds he withheld the means for worship and sacrifice and withheld part of what was asked, so it did not amount to letting Israel go as God required. He chose to receive the plagues rather than submit, watching his whole kingdom lie under dreadful judgments without remorse and persisting in rebellion even after Egypt was ruined.
Moses refused the condition and insisted that every animal must go with them with not a hoof left behind, taking every head of cattle and every sheep, because the animals were needed for sacrifices and burnt offerings and they did not know with what they must serve God until they came there. That refusal led directly to the warning that the angel of God would slay the firstborn. It was the last plague more severe than any before it, opposed to the last by the king and his idolatrous priests, coming on the terrible night for the Egyptians and glorious night for the people of God when the solemn ordinance of the Passover was instituted. Delivering Israel was hard and required destroying the prosperity of all Egypt, and after the firstborn were dead Pharaoh told them to go quickly, yet still to leave their livestock, and Moses refused until Pharaoh had to consent to take all the cattle along and God led them out.
The offer and Pharaoh's threat that Moses shall die if he sees his face again show a heart hardened against the Lord despite all signs and mighty wonders. His haughty pride was annoyed by Moses' firm, fearless courage, and his blindness lay in not realizing that in contending against Moses and Aaron he contends against the mighty Jehovah, Maker of the heavens and of the earth. By contrast Moses stands with strong faith and unshaken confidence in God, elevated above fear and fitted to lead Israel, with favor among the people as a very wonderful man whom the king would not dare to harm.