ash scoop (tea ceremony)
A small, flat utensil used in the Japanese tea ceremony to shape and smooth the ash in the hearth (炉) or brazier (風炉).
茶道では、灰匙で炉の灰を整えます。
In the tea ceremony, you shape the ash in the hearth with an ash scoop.
Compound of 灰 (hai, 'ash') and 匙 (saji, 'spoon'). The reading さじ for 匙 is a common kun'yomi.