Nor might of mortal eye be ever seen > [No mortal eye might ever look upon it]

3 Not made of steel, nor of enduring brass 4 (Such earthly metals soon consumed been):

been > [would have been]

5 But all of diamond perfect pure and clean

clean > unpatterned, unadorned

6 It framed was, one massy entire mould,

framed > fashioned, made massy > solid, weighty entire > [in one piece] mould > shape

7 Hewn out of adamant rock with engines keen,

adamant rock > diamond engines > tools, machines keen > sharp

8 That point of spear it never pierce could,