मांसान्यस्य शकराणि किनाटँ स्ना-व तत्स्थिरम् ।अस्थीन्यन्तरतो दारूणिमज्जा मज्जोपमा कृता ॥ ३ ॥
In plain words
His flesh is the tree's woodchips. That tough inner layer of bark is his sinew. His bones are the tree's timber, hidden underneath. And marrow — that one doesn't even need translating. It's just marrow, in both of them, exactly alike.
Close to the Sanskrit
His flesh is [as] chips [to a tree]; the inner bark-fibre — that is the firm one — is [as] sinew; the bones are, on the inside, as the pieces of wood; the marrow has been made in the likeness of marrow.