There are two ledges, one above the other, each a handbreadth wide, and there is a cubed handbreadth between them. [If there is] tumah underneath them, whatever is underneath them becomes tamei. [If there is tumah] between them, whatever is be-tween them becomes tamei. [If there is tumah] above them, whatever is directly above it, up to the sky, becomes tamei. [If] the upper one extends beyond the lower one by a handbreadth, and tu-mah is underneath or between them, whatever is underneath or between them be-comes tamei; [if there is tumah] above them, directly above it, up to the sky, becomes tamei. [If] the upper one extends beyond the lower one by less than a handbreadth, and tumah is underneath them, whatever is underneath them or between them be-comes tamei. [If there is tumah] between them or beneath the extension, R’ Eliezer says: Whatever is underneath them or between them becomes tamei. R’ Yehoshua says: Whatever is between them and whatever is underneath the extension becomes tamei, but whatever is underneath [the ledges themselves] remains tahor.