There was no quick means of communication; how did jews know they could leave?
Why did the Egyptians heed the jewish "Lord" this time and no other re taking their raiments?
12:35 And the children of Israel did according to the word of Moses; and they borrowed of the Egyptians jewels of silver, and jewels of gold, and raiment:
12:36 And the LORD gave the people favour in the sight of the Egyptians, so that they lent unto them such things as they required. And they spoiled the Egyptians.
12:37 And the children of Israel journeyed from Rameses to Succoth, about six hundred thousand on foot that were men, beside children.
12:38 And a mixed multitude went up also with them; and flocks, and herds, even very much cattle.