Emptiness brings Light...

It is not the solid wood that can become a flute, it is the empty reed.

Bowl of Saki, by Hazrat Inayat Khan
Commentary by Pir-o-Murshid Inayat Khan:

There is a saying of Jalaluddin Rumi, 'Fire, water, air, and earth are God's servants, and whenever He wishes them to work for Him, they are ready to obey his command.' If the elements are the obedient servants of God, cannot man be a greater and better instrument?

In point of fact God Himself is the messenger. In the aspect of God He is God, but, in the form of the messenger, He is the messenger. The tide of the sea surges, and when the sea has that motion it is called tide, but in reality the tide is the sea itself.

It is not solid wood that can become a flute, but the empty reed. It is the perfection of that passiveness in the heart of the messenger which gives scope for the message from above; for the messenger is the reed, the instrument. The difference between his life and the life of the average man is that the latter is full of self. It is the blessed soul whose heart is empty of self, who is filled with the light of God.