Then the priest shall go out of the house to the door of the house, and shut up the house seven days:
And the priest shall come again the seventh day, and shall look: and, behold, if the plague be spread in the walls of the house;Leviticus 14:39 KJV
And he shall look on the plague, and, behold, if the plague be in the walls of the house with hollow strakes, greenish or reddish, which in sight are lower than the wall;Leviticus 14:37 KJV