Why of Dust?

"Man is made from the dust,

---that he may remember
that he is nothing in himself;
---but also in the image of God, that he may know the infinite possibilities before him - association with God Himself;"
E.J. Waggoner
And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
Genesis 2:7