تفسير : ((it is) of the awful tidings) they are talking about the tidings of the noble, glorious and great qur'an,
Jalāl al-Dīn al-Maḥallī
تفسير : about the awesome tiding ([this is] the explication of that ‘thing’; the interrogative is meant to emphasise its magnitude) — this [awesome tiding] is the qur’ān, comprising [news of] the resurrection and so on, which the prophet (s) brought —