The signature, Zhiyan, is the designation of the distinguished early Qing dynasty carver, Zhou Hao, who specialised in carving landscapes in the style of the Southern Song and Yuan masters. The cyclical Bingchen date probably corresponds to 1736.
The present wrist-rest with its unique slidable tab is highly unusual as it would have been difficult to carve. Such work would have required skill and precision in cutting away the underside of the square so as to enable it to move along the groove. It is possible that the present wrist-rest also served its function as a space guide when writing in small kaishu, standard script, by sliding the tab in-between the incised characters. Compare a wrist-rest bearing Zhou Hao's signature from the collection of Mr Ho Tzu-chung, carved with downward sweeping bamboo, but without the additional guidance tab, illustrated in Chinese Bamboo Carving, Part I, Hong Kong, 1978, p. 330, no. 98.