Sentence:  Then his son bought a carven coffin hewn from a great log of fragrant wood which is used to bury the dead in and for nothing else because that wood is as <WSD>lasting</WSD> as iron, and more <WSD>lasting</WSD> than human bones, and Wang Lung was comforted. 
Meaning of the word marked with <WSD> tags:  Persisting for an extended period of time.