[If] a zav is supported by the bed and by the mizran, [it] transmits tumah to two and invalidates one, these are the words of R’ Meir. R’ Yose says: [If] a zav is supported by the bed and by the mizran, [the first] ten handbreadths [of the mizran] transmit tumah to two and invalidate one. [The part of the mizran] from ten [handbreadths] and outward transmits tumah to one and invalidates one. [If a zav] is supported by the mizran, from ten [handbreadths] and inward, it is tamei. From ten [handbreadths] and outward, it is tahor.

[If] a bed was tamei midras, and one wound a mizran around it, the entire [bed] is tamei midras. [If the mizran is] removed, [the bed itself] is tamei midras, and the mizran is [tamei due to] contact with a midras [hazav]. [If the bed] was tamei with seven-day tumah, and one wound a mizran around it, the entire [bed] is tamei with seven-day tumah. [If the mizran is] removed, [the bed itself] is tamei with seven-day tumah, and the mizran is tamei with evening-tumah. [If the bed] was tamei with evening-tumah, and one wound a mizran around it, the entire [bed] is tamei with evening-tumah. [If the mizran is] removed, [the bed itself] is tamei with evening-tumah, and the mizran is tahor.