David's mission was to restore the kingdom after the failure of this previous king.
Saul
While people look at the outward appearance, this is what the Lord looks at.
This is the object Samuel used to hold the oil for the anointing.
The horn
This was the specific "Introductory Speech" or command God gave to Samuel.
"Rise and anoint him; this is the one."
The person who provided the "objection" by implying that David wasn't worth mentioning.
Jesse (David's father)
This was David's job when Samuel arrived in Bethlehem.
Tending to the sheep.
This was the two-part mission of David: to acknowledge God's word and to do this for the people of Israel.
Physical appearance and not being a firstborn.
This event serves as "The Sign" that the anointing was real, involving the Spirit of the Lord.
The Spirit coming powerfully upon David.