It is to be noted...
Following the narrative of the person who had asked for Divine torment, the blessed Verse in question treats of Resurrection and the torments in store for sinners on that Day, saying that the angels and the spirit ascend toward God Almighty on a Day whose measure is fifty thousand years. The ascension of the angels indubitably implies spiritual ascent rather than the physical one.
In other words, they hasten toward nearness unto God Almighty and on that Day, namely the Day of Resurrection, they are prepared to receive Divine Commands and implement them, as it was mentioned above under 69:17 that "and the angels will be on its sides" implies that they will surround the heaven and will be prepared on that Day to act upon Divine Commands.
The spirit (ruh) herein implies the archangel, namely the trusted spirit (ruh al-amin) or Gabriel, to whom there is a reference elsewhere in the Holy Qur’an ^4 : "Therein descend the angels and the spirit by Allah’s Permission with all Ordainments." The angels and the 'spirit' descend by Divine Permission on the night of Ordainment (laylat al-qadr) to implement Divine Ordainments and Decrees.
It is worthy of note, however, that the word ruh implies different senses according to the contextual meaning, e.g. man’s spirit, the Holy Qur’an, the Holy Spirit (ruh al-qudus), the archangel of Revelation, as attested in different Qur’anic Verses.
The expression "fifty thousand years" reflects that the Day of Resurrection shall last fifty thousand years, taking into account the passage of time in this world which does not stand in disharmony with the "one thousand years" mentioned elsewhere in the Holy Qur’an ^5 , since according to traditions, there shall be fifty stations on the Day of Resurrection each of which shall last one thousand years.[^6] Some Qur’an exegetes have also suggested that the number "fifty thousand" herein implies multiplicity rather than quantity, namely that Day shall last long.
At any rate, it concerns the sinners, wrong doers, and disbelievers.