Exodus 5:3
And they said, The God of the Hebrews hath met with us: let us go, we pray thee, three days’ journey into the desert, and sacrifice unto the LORD our God; lest he fall upon us with pestilence, or with the sword. And they said, The God of the Hebrews hath met with us: let us go, we pray thee, three days’ journey into the desert, and sacrifice unto the LORD our God; lest he fall upon us with pestilence, or with the sword.
Moses and Aaron asked Pharaoh to let the Hebrews go three days' journey into the desert to sacrifice to the LORD their God. The leave they sought was deliberately modest, asking for only a brief absence for worship. The warning joined to the request was that failure to worship might bring pestilence upon the people, or death by the sword.
The call to leave Egypt was that Israel might worship God and keep His Sabbath, and Moses was seeking to restore Sabbath observance that bondage had led Israel to neglect. Pharaoh refused the request, professing to be entirely ignorant of Israel's God and unwilling to recognize or obey Him. He treated the plea for worship as idleness and answered it by intensifying Israel's forced labor.
God used the encounter to show Pharaoh that His voice must be obeyed, that He is above all, and that He will compel proud rulers to bow to His authority. Israel's departure from Egypt foreshadows God's final call for His people to leave Babylon so they will not worship the beast or its image.