Some say that it refers to all the three groups and hence...
Some say that it refers to all the three groups and hence all of them would be admitted to Paradise and some say it refers to those selected persons about whom it has been said: “those whom We chose.” And some are of the opinions that it refers to he who takes a middle course and “foremost” and that he who makes his soul to suffer a loss is not included in it as some traditions related to this matter show.
For instance it is reported in Maniul Akhbar that Imam Sadiq (a.s.) said that the oppressor always obeys his desires and that a he who takes a middle course always goes on thinking in his heart, that is, he is always trying to improve his beliefs or is busy reforming his soul or he worships constantly and that even in the matter of worldly affairs he keeps religion in his mind.
And the “he who is foremost in deeds of goodness” revolves round his Lord and he empties his soul of all desires and ambitions and is not concerned with anything but the pleasure of his Lord. Likewise, Imam Baqir (a.s.) is reported to have said that among the pure progeny of the Messenger (S) of Allah the oppressor is the one does not recognise the rights of the Imam and the middle course is one who believes in the leadership of the Imam and the foremost in deeds of goodness is the Imam himself.
Imam Sadiq (a.s.) is quoted in Majmaul Bayan that he adds after the aforesaid quotation “all of them will be pardoned” and that Gardens of perpetuity, they shall enter therein… means that the foremost and the middle course ones would be admitted to the Gardens of Adn. Similarly, according to reliable sources, Imam Baqir (a.s.) is reported to have said that, (when people asked from him the explanation of the above mentioned verse): It has been revealed in praise of we, Ahlul Bayt (a.s.).
Abu Hamza Thumali (r.a.) says I asked: Who from among you is the one who oppresses his soul? The Hazrat replied: From us Ahlul Bayt such person is he whose sins and rewards would be equal. He would be considered as the one who oppressed his self as he has been found wanting in the Worship of Allah. I asked: Who from you is of the middle course?
He replied: He is the one who worships Allah both in difficulties and in ease or both when truth is dominant or untruth is in power until he breathed his last. Then I asked: Who is the foremost in deeds of goodness among you?