so awesome and deep, I hope that others will be inspired to share their understanding as well

This parable is the first in the text to be told by a member (or members) of the assembly. Subhuti, that great and kind disciple, addresses the Buddha and speaks a parable to illustrate the sravakas understanding of the Teaching of the One Vehicle. I think it is well to point out he stresses a
contentment with the spiritual attainment he has achieved before the teaching (content with non-function, formlessness and the void) and had no desire for the attainments of another path (the deeds and practices of the bodhisattva) or Buddhahood or Perfect Enlightenment. It is not that this goal is not worthy of pursuing, the Hinayana vehicle is a very individualized way of practice and Individual Enlightenment is ample goal. Separate paths are seen as just that, separate, before the teaching was given.
It must be said from the start that this parable is outside time, it begins by stating- "it is like a man who, in his youth, leaves his father and runs away." The first cause (separation) happens before the story itself and time runs rampant toward eternity at the end.
In the parable, the son leaves home for a long time and becomes needy and concerned with obtaining necessities then
unexpectedly approaches his native country. The father at first searches for his son but, to no avail and, building his wealth great, settles in a new place where the son would never find him. The father is our true nature personified, The Buddha-nature, which we have been separated from since beginning-less time. The son is us, the separated identity. The father has desire to transmit his wealth to his son. When the son does happen to the fathers residence, he sees its greatness and becomes afraid and confused. The father recognizes his son and sends men to bring him over and the son replies with fear and faints away. Our true nature (Buddhahood) always knows us. It is we who have become alienated and see it as great, worthy, either attainable or unattainable, desired/undesired, etc. The fathers tactful means (in the Sutra
device) for attracting his son is to hire him. His work of clearing dust is a loaded symbol given later as "all inferior laws and things" and he is happy with the comparatively meager conditions. As the father is our Buddha-nature personified (the Buddha), he approaches the son by appearing more humble and low. He puts complete confidence in him and offers unlimited support. Compared to the actions taking place, time flies by. The father then by tact, makes the son acquainted to his wealth. The abundant treasure (our true nature) is gradually more accepted and the son (our identity) is more comfortable with greatness and power. Then the day comes when the father proclaims to all at once the story, true identity and true wealth of the son. He completely relinquishes all abundance to the son. The son (disciples as separate identities) sees now and forever, eternity, filled with comfort and power.
Subhuti explains that the teaching has come of its own accord, our true nature as Buddha-nature is ours already and must only be revealed. The only way, the only path where the goal is full and complete Enlightenment or, Buddhahood, is the Bodhisattva path. It is/was the Buddha Sakyamuni's path and, indeed the only "True" path, the One Vehicle. It is understood from this view that Nirvana is a lesser degree of attainment. One thing that is supremely beautiful to me is how Subhuti points out that the Buddha does not begrudge anyone upon any stage of the path, all laws are given as needed to anyone who is receptive. This Wonderful Law is given so that all may understand their true nature and practice for the sake of all. In the understanding of True Reality, there is no distinction between self and other and that was well understood but, this Sutra stresses the fact that there is no individual attainment.
There is much more that can be said about this parable, hopefully some will be inspired to share their own understanding for the sake of the better understanding of others, as I have tried to here.