寝苫枕块

qǐn shān zhěn kuài

bed of straw and pillow of clay (idiom)

the correct etiquette for a filial son during the mourning period

寝

qǐn

old variant of 寢|寝[qin3]

苫

shān

straw mat

枕

zhěn

(bound form) pillow

块

kuài

lump; chunk; piece