[If] there is a skylight that is the size of a square handbreadth in a house, [and] there is tumah in the house, whatever is directly opposite the skylight remains tahor. [If] the tumah is directly opposite the skylight, the house remains tahor. Whether the tumah is in the house or directly opposite the skylight, [a person] who places his foot above [the skylight] combines the tumah. [If] part of the tumah is in the house and part of it is opposite the skylight, the house becomes tamei, and whatever is directly opposite the tumah [also] becomes tamei.