Commentary explaining the meaning of the ayahs. One passage often covers several ayahs, so neighbouring ayahs can show the same text.
English Al-Mukhtasar tafsir for Surah Al-Mursalat — Ayah 4
فَٱلۡفَٰرِقَٰتِ فَرۡقٗا ٤
And He also takes an oath on the angels that descend with that which differentiates between truth and falsehood.