The Arabic word mutraf is applied to one who is vain and...
The Arabic word mutraf is applied to one who is vain and rebellious owing to indulgence in mundane pleasures.[^1] It is true that all the people on the Left Hand are not amongst those indulging in affluence and those who disobeyed Divine Commands. The Holy Qur’an refers to their chiefs. Likewise we notice that corruptions in human societies are due to the vanity and obduracy of those who lead others astray.
Such wrong-doers are the main sources of all the battles and bloodsheds and concupiscent inclinations. Thus, the Holy Qur’an above all points at them. It is worthy of note that Blessings include youth, health, and long life besides material possessions which should be employed toward Divine Satisfaction. The blessed Verse 46 is saying that they persisted in committing grave sins.
The Arabic word hinth originally denotes any kind of sin, but the word is mainly applied to breaking one's promise and turning away from one's word, since they are manifest instances of sins.
Thus, the characteristics of the people on the Left Hand does not solely lie in committing sins, but their persistence in committing grave sins, since the people on the Right Hand may commit sins as well, but they never persist in committing sins and when they see that they have sinned, they immediately repent.
Some Qur’anic exegetes interpret the Arabic phrase hinth ‘adim as polytheism, since it is the gravest sin as it is reflected elsewhere in the Glorious Qur’an: "Indeed, Allah forgives not that partners be associated with Him in worship, but He forgives except that anything else to whom He wills; and whoever sets up partners with Allah in worship, he has verily invented a grave sin." Some also maintain that: "grave sin" is applied to lying which is the gravest sin and the source of committing other grave sins, particularly instances which entail denial of Prophets (as) and Resurrection.
However, the general meaning of the blessed Verse reflects that these are all instances of "great sin." The blessed Verse 47 is saying that their evil deeds included their saying that when they die and turn into bones and dust, they may not be raised from the dead. Thus, denial of Resurrection is the source of many a sin and the same constitutes another characteristic of the people on the Left Hand.
The expression: "they used to say" reflects that they persisted in the denial of Resurrection even though they witnessed the scenes of Resurrection in this world.