Exodus 12:22-23

22Take a bunch of ahyssop and bdip it in the blood that is in the basin, and touch cthe lintel and the two doorposts with the blood that is in the basin. dNone of you shall go out of the door of his house until the morning. 23 eFor the Lord will pass through to strike the Egyptians, and when he sees the blood on fthe lintel and on the two doorposts, the Lord will pass over the door and gwill not allow the destroyer to enter your houses to strike you.
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