[Regarding] a bed that was tamei midras, [if] a short board is removed along with two legs, it is tamei. [If] a long board [is removed] along with two legs, it is tahor. R’ Nechemiah rules [it] tamei . If one broke off two diagonally [positioned] tongues, or he broke off two diagonally [positioned] legs ([breaking off] a handbreadth [from one,] and a handbreadth [from the other]), or he lowered [the bed to a height of] less than a handbreadth, [the bed is] tahor.