This beam is related in design to a part of a beam in the David Collection, Copenhagen, carved with a bevelled design, which is almost certainly a part of a beam sold in these rooms (April 23 2001, lot 135) which has been dated to the first half of the 12th century.
The present piece is probably of slightly later date, having lost the simplicity of design and attained a more baroque appearance.
von Folsach, K: Art from the world of Islam, Copenhagen, 2001, no. 435, pp. 270-1.