At what point did the Prodigal son begin to trace his steps back home? It was not his hunger that pull the string. In his hunger he looked for alternative ways to satisfy himself. But the realization of his Father's mercy summoned him to a deeper reflection, and the subsequent steps back home followed. Every genuine repentance is prompted by God's mercy.
"I will say to him, 'Father, I have sinned against heaven and against you. I am not worthy to be called your son, treat me as one of your paid servants."' For repentance not remain as mere psychic imagination, or a sensational good wish, there is need for confession. By its very nature confession needs a witness and acceptance. In this way, repentance is no more a mere private affair. Confession of sins is a concrete expression of contrition and a source of assured forgiveness. It is a crucial step along the journey back home.
While the Prodigal son was still a long way off, the father ran to meet him, embraced and kissed him. This implies that even before the boy began his journey home, the father's mercy awaited him. That means the father had already embraced him in his heart before running down to meet him. At this meeting point of mercy and contrition, the father first 'confessed' his love for his son through the concrete gesture of hug and kiss, even before the boy confessed his sins and contrition.