This indicates that what Christ as our High Priest holds is not dust; He holds the transformed saints, typified by the onyx stones on the shoulder-pieces of the ephod worn by the high priest.
When some saints hear this, they may feel discouraged, thinking that they have not been transformed. They may say, “If Christ holds only onyx stones, and not dust, then I am through with the experience of being held by Him. I feel discouraged because I have not yet been transformed into onyx stone.” Actually you do have the experience of being held by Christ. Furthermore, you do have some amount of onyx stone. Often you may feel as if you are falling away from the Lord. But it is the dust that is falling, not you. Sometimes the Lord raises up an environment which causes us to be shaken. We may be afraid of falling away. However, only the dust is shaken away. We ourselves as regenerated ones will never be removed, for the onyx stone in us will never fall. The onyx stone remains, placed in the beautiful and glorious settings of gold.