The majority of the exegetes opt for the former...
The majority of the exegetes opt for the former, though some prefer the latter, maintaining that a clause may not be opened by the redundant la, but the emphatic particle occurs in the middle of the clause. However, the former interpretation sounds to be further befitting, since the Qur’an swears by things more significant that the Day of Resurrection, e.g. the Pure Essence of God Almighty. Thus, it would be quite natural to swear by the Day of Resurrection herein.
Furthermore, the occurrence of the redundant la is common in Arabic. In this respect, certain opening lines by the pre-Islamic poet Imra’ al-Qays have been quoted which are indicative of the usage of the redundant la in the Arabic tongue. We maintain that discussing the redundancy or the negation of the la is not that significant, since the usage entails the same result, namely the significance of the object of the oath.
The point is that the existence of conscience in the heart reflects the inevitable Resurrection, as human soul is brimmed with happiness upon doing good righteous deeds and it is thereby rewarded. Au contraire, the soul is severely tormented and chastised upon committing evil deeds, such that man may commit suicide in order to deliver himself from pangs of conscience; thus, the verdict as to the severest punishment is issued by conscience and man executes the verdict.
The reflection of the self-reproaching self in human soul is so wide ranging that it may be studied and investigated from any aspect. Taking into account the truth that there is a small means of trial in the microcosm, i.e. human existence, how may one imagine that the macrocosm with all its majesty be deprived of a great just tribunal? Thus, we learn about the inevitability of the Day of Resurrection through the conscience in human heart.
The interesting link between the twain oaths are thereby manifested. In other words, the latter oath serves as an argument substantiating the former. Qur’an exegetes suggest different interpretations for the nature of the self-reproaching self. A well-known interpretation was already mentioned according to which human conscience reproaches man upon his committing evil deeds and makes him to revise and compensate his past evil deeds.