'Door posts' in the Bible

They must take some of the blood and put it on the two doorposts and the lintel of the houses where they eat them.

The blood shall be a sign for you on [the doorposts of] the houses where you live; when I see the blood I shall pass over you, and no affliction shall happen to you to destroy you when I strike the land of Egypt.

Take a cluster of hyssop, dip it in the blood that is in the basin, and brush the lintel and the two doorposts with some of the blood in the basin. None of you may go out the door of his house until morning.

When the Lord passes through to strike Egypt and sees the blood on the lintel and the two doorposts, He will pass over the door and not let the destroyer enter your houses to strike you.

then his master must bring him to the judges, and he will bring him to the door or the doorposts, and his master will pierce his ear with an awl, and he shall serve him forever.