The souls of mankind can be categorized under three headings: the first is the group that is totally unjust and does not deserve to be sworn by for it does not have the inclination to reach for perfection and so it is not a sign of the Day of Judgment. It is the “Nafs Ammara” that instigates the soul to evil.
The second group is the one ( Nisf Nurania) which soars up for perfection and is awaken when ever it commits any error to curse itself, an admonishment that become the way to perfection.
This soul is worth the value and is an example of the Day of Judgment. It is called Nafs Lawama.
The third group is totally divine and crosses the stage of conscience to reach the realm of peace and is addressed as “Ya Ayyatohan Nafsol Mutmainna” and by the word “Arjiiy” reaches out to perfection and is counted among the pure people of God. And he reaches the stage where “He is happy with God and God with him”. (Raaziatan Marzia)
In short the explanation and argument of this verse means that as per the eloquence of the Qura’n it is not abrupt or incidental for two oaths to be taken together but there should definitely be a link between the Day of Judgment and the Conscience. That link is that if a person is not misguided by wrong ideas from his inherent nature then he has the realization and the conscience which admonishes him for wrong doings and invites him to goodness.
This realization is a personal realization that inside a person acts like a minor court of justice; it highlights the fact that in such a big universe there should be a greater realization of knowledge that stands to punish the wrong doers. So the symbol of this great realization is the Day of Judgment.