A few points especially struck me as we worked our way through the parable:
1) The younger son (the "prodigal") essentially told his father "drop dead" when he asked for his inheritance early.
2) Even when the younger son "came to his senses" and set off to return home, he was rehearsing a speech that, if delivered, would have expressed his desire to be a cared-for servant, but not a close family relative.
3) When the Father runs out to meet him to kiss his face and embrace him, the son isn't even able to finish his rehearsed speech... the grace and love of the Father interrupt him with the giving of the ring and the robe. This was the moment of the son's true repentance: the moment he opened himself to receive the love of the Father.
I also heard a sermon some years ago in which the speaker argued that the older son is the antithesis of what Jesus was in reality. Because the younger son had squandered his inheritance, it was only at the cost of the older son's share that the younger could be re inherited. The older son in the parable is a self-righteous and hard-hearted character, who despised his brother rather than going after him to bring him home. Not only does Jesus go after the "prodigals", but it was at the cost and sacrifice of his own life that we are brought back into the family of God. Our inheritance in God's family is a shared inheritance with the Son of God, and so Jesus is the "firstborn among many brothers and sisters" (Romans 8:29).
In writing this song, I most of all wanted to capture the image of the Father running to embrace his returned son. I want to experience that embrace each day of my life, remembering afresh my need for the Father's inexplicable and extravagant love. "O the Father's love is overwhelming!"
You kissed my face when I was your foe
Father you called me home
I had returned to beg at your feet
Here you embraced me
O the Father's love is overwheling
Covering all my shame
See the Father run, His arms embrace me
Lifting me up in his grace
Riches unheard of squandered in sin
I spent my inheritance
Now at the cost of your innocent Son
You made a way for love
Heaven and earth, when have you heard
When have you seen such a thing
Wonder of wonders, the heart of the Father
You welcome the prodigal in