During rites of esoteric Buddhism (mikkyō), katsuma are placed at the four corners of the altar to bind off the ritual space. This example of a katsuma is in a relatively large scale, with great strength to its thick and bold form. Its sharply shaped prongs evoke the origin of mikkyō ritual implements in weaponry. Later, elements of katsuma would become stylized. This example is thought to date back to the Tang dynasty (618–907) in China since it seems to precede conventionalized katsuma forms.
 
MIMOTO ShusakuEnglish by Mary Lewine 
Buddhist Art Paradise: Jewels of the Nara National Museum. Nara National Museum, 2021.7, p.339, no.134.