Exodus 12:11-12

11 This is how you must eat the lamb: Dress yourselves so that you are ready to travel. Put your shoes on your feet. Take your stick in your hand. Then eat the food quickly. This is the Passover meal which shows that you obey me, the Lord.

12 On the night that you eat the Passover meal, I will travel through the country of Egypt. I will kill every firstborn son and every firstborn male animal. I will punish all the gods of Egypt. I am the Lord.