shaku

…carries an ivory tablet (shaku), undoubtedly inspired by jade tablets carried by Chinese emperors as symbols of imperial power.

Priests usually carry a shaku, a flat wooden sceptre, either held in the hand or thrust into the belt.

However, the ivory tablet (shaku) carried by the emperor when wearing the sokutai was undoubtedly inspired by tablets of jade that Chinese emperors carried as symbols of their imperial power.