In the story, a man had two sons. The younger demanded his share of his future inheritance immediately, whereupon the father divided it between his two sons.
The younger son leaves the estate and goes into a far country, wasting his entire inheritance on sinful pleasures, and immediately thereafter a famine hits the land. The son is forced into working for a man, feeding pigs yet still so famished that he wanted to eat what the pigs were eating.
Eventually coming to his senses, he decides on a final, desperate act: he would return to his father, admit his wrong and his unworthiness to be called his son, and beg to be hired as a servant. But while he was still a long way from home, his father sees him and runs to him and before the son can finish his prepared speech, the father embraces him and calls for a celebration with the "fatted calf" as the main course (saying his son was dead, and has come back to life).
The eldest son (who stayed with the father) heard the noise and was told of the events. Angry, he refused to attend. When his father pleads with him to come, he replies that he kept all of his father's commandments, yet never got any animal where he could have a party (even though he now owned 2/3 of the inheritance, which he likely increased during his ownership), yet "this son" (refusing to acknowledge him as his brother) gets rewarded after wasting his share of the inheritance. His father replies that all he has is the elder son's, but still believes a celebration is in order as his brother has (metaphorically) returned from the dead.
The interpretation is fairly simple: the father in this story is God, the eldest son represents those who believe good works earn God's favor (specifically the Jewish leaders, who meticulously kept the Law) while the younger son represents those in humanity who (realizing the error of their ways) return to God, who forgives them for their sins because they asked to be.
- Under Jewish custom, an inheritance was divided into X + 1 shares, where X is the number of male heirs greater than one; the oldest male heir is given an extra share, as he would be responsible for the care of his now widowed mother.
- Pigs are unclean animals in Jewish law; thus making his profession equivalent to "hitting rock bottom".
- In Jewish culture, fathers did not run to their children.