BT Ber 6a(13) :לייתי קיטמא נהילה וליהדרה אפוריה‏ : let him bring sifted ashes and put them around his bed
See the entire entry for nḥl vb. to sift

BT Ber 6a(13) :
See the entire entry for pwry#3 n.m. bed