For Yahweh will pass through to strike the Egyptians and when he sees the blood on the lintel and on the two sideposts Yahweh will pass over the door and will not allow the destroyer to come in to your houses to strike you

Add punctuation
For Yahweh will pass through to strike the Egyptians; and when he sees the blood on the lintel, and on the two side-posts, Yahweh will pass over the door, and will not allow the destroyer to come in to your houses to strike you.