How we cite our quotes:
he whistles his Jews into rows has them shovel a grave in the ground
he orders us strike up and play for the dance (lines 9-10)
The Jews could either be shoveling graves for themselves or for others in the camp who have died recently. Either way, they are confronted with the possibility of death at any moment, which is part of the idea behind the whole "we're drinking black milk at all hours" thing. As if that weren't bad enough, the guard forces some of the Jews to play a "Deathfugue" or "Death Tango."
he writes when it grows dark to Deutschland your golden hair Margeurite
your ashen hair Shulamith we shovel a grave in the air there you won't lie too cramped (lines 15-16)
Shulamith's "ashen" hair reminds us of smoke and the "grave in air" that is mentioned throughout the poem. The bodies of Jews in the Holocaust were often burned in crematoriums, and they were denied graves and the religious rites of a funeral. A mysterious voice within the poem tries to make up for this loss by offering the thought that "there you won't lie too cramped." Whose voice is this?
He shouts play death more sweetly Death is a master from Deutschland
he shouts scrape your strings darker you'll rise then in smoke to the sky
you'll have a grave then in the clouds there you won't lie too cramped (lines 25-27)
Death is everywhere in this poem, isn't it? First, "death" is the name of the song the Jews are playing, and which the guard cruelly wants them to play "more sweetly." Second, death is "a master from Deutschland." It's as if death itself has taken over Germany and is running the country. Finally, it seems that the guard might have been that mysterious voice luring the Jews toward a "grave […] in the clouds."