'Door post' in the Bible

And they shall take of the blood, and strike it on the two side posts and on the upper door post of the houses, wherein they shall eat it.

For the LORD will go about and smite Egypt. And when he seeth the blood upon the upper door post and on the two side posts, he will pass over the door and will not suffer the destroyer to come into your house to plague you.

Then his master shall bring him unto the judges; he shall also bring him to the door, or unto the door post; and his master shall bore his ear through with an aul; and he shall serve him for ever.