Numbers 33:3-5

3They left Rameses in Egypt on the 15th day of the first month. That was the day after the Passover meal. The Israelites marched out bravely, while all the Egyptian people watched them.

4As they left, the Egyptians were burying all their firstborn sons, because the Lord had killed them. The Lord had shown his power over the Egyptians' gods.

5They left Rameses and they travelled to Succoth. They made their camp there.