Sentence:  And He laid down for him certain conditions : so that , if he kept the command of God , then he would always remain as he was , that is , immortal ; but if he did not , he would become mortal , melting into <WSD>earth</WSD> , whence his frame had been taken '' . 
Meaning of the word marked with <WSD> tags:  the loose soft material that makes up a large part of the land surface