From the woods themselves it goes into the axe
The sense is clear, but the reading is doubtful. Another possible rendering is: "The axe goes into the wood from which [it originally came]." Dukes appositely quotes the following from the Midrash : "When iron was created, the trees began to tremble. The iron thereupon said to them, Wherefore do ye tremble? Let none of your wood enter into me, and not one of you shall be hurt." The handle which enables one to use the axe for felling trees is obtained from the trees themselves.