cedar of lebanon or seed of mustard?

Luke 13:18-19
18 So He was saying, "What is the kingdom of God like, and to what shall I compare it? 19 "It is like a mustard seed, which a man took and threw into his own garden; and it grew and became a tree, and THE BIRDS OF THE AIR NESTED IN ITS BRANCHES."

Brilliant verse here. Many scholars think that Luke is playing on a metaphor that was common among the religious crowd of his time. They compared themselves to the great “cedar of Lebanon” which was a large tree that would house the large, beautiful birds. The symbolism was that they would become a great and powerful nation made up of powerful rulers. Jesus re-defines this metaphor by saying that his kingdom is more like a mustard seed. Jesus’ uses the metaphor of a tree that has a small beginning, grows slowly, spreads and overtakes everything around it, and is shelter for the ugly, unwanted birds. I am tempted to make this connection and describe what all I think this means for us Christ followers, but I will leave it open ended for now for you to give it some thought.