[If] a bed was wound with a mizran, and a corpse touches them, they are tamei with seven-day tumah. [If] they separate [from each other], they are tamei with seven-day tumah. [If] a sheretz touches them, they are tamei with evening-tumah. [If] they separate [from each other], they are tamei with evening-tumah. [Regarding] a bed whose two long boards were removed, and one fashioned new [boards] for it, and he did not alter the notches, [if] the new [boards] broke, [the bed remains] tamei. But [if] the old [boards broke, the bed is] tahor, for everything depends on the old [boards].