מַשְׁקוֹף

They are to take some of the blood and put it on the sides and tops of the doorframes of the houses where they eat the lambs.

Take a cluster of hyssop, dip it into the blood in the basin, and brush the blood on the top and sides of the doorframe. None of you shall go out the door of his house until morning.

When the LORD passes through to strike down the Egyptians, He will see the blood on the top and sides of the doorframe and will pass over that doorway; so He will not allow the destroyer to enter your houses and strike you down.