And in the entrance of the sixth palace Dumiel the Prince guardeth the sill of the right [side] of the entrance of the sixth palace, sitting on a chair [wrought] of a pure gem which [hath] in it the splendour of the luminaries of the firmament such as [they were at] the creation of the world. (Fortunate Day. Best of luck. Show the sign. Peace. The Lord God of Israel) And Dumiel the Prince receiveth him kindly and seateth him upon a chair wrought of a pure gem, and himself sitteth beside him at his right.
Dumiel Guards the Entrance to the Sixth Palace
Heikhalot Rabbati 21:3