Tonight we learned that the believers prepared for the final plague by sacrificing sheep and smearing the lintel of their house with the blood. In this way the angel Azrail (a) would pass over the house and not take the firstborn child.
My son wanted to know why this blood protected the house. I said that I wasn’t sure but I thought that sacrificing in the name of Allah (a) and obeying his prophet protected the house.
We also learned of an old Egyptian lady that led Musa (a) to the tomb of Prophet Yusef (a). His sarcophagus was raised so Yusef (a) could accompany the believers out of Egypt.