What does the coffins stacked againest a school house wall symbolize in the book? support with references

THe coffins are foreshadowing as well as symbolic. They are there for most of the men who will not come back from battle alive. They are an ominous symbol of impending death for Paul and his comrades,

“’They’re for us,’ growls Detering. ‘Don’t talk rot,’ says Kat to him angrily. ‘You be thankful in you get so much as a coffin,’ grins Tjaden, ‘they’ll slip you a waterproof sheet for your old Aunt Sally of a carcass.’

Although the book does go indepth with the symbolisation of many items Marcus' neck is still not visible throughout the novel.

Aslan is out here answering questions at 6:09 am like a fuckin champion, does this man even sleep