Overall meaning : This noble surah opens with an Arabic letter of the alphabet, saad—one of the ‘disconnected letters’ which have already been discussed at the beginning of Surat Al-Baqarah.
The Almighty then swears by the Noble Qur’an which is full of reminders that the truth is by no means what the unbelievers claim it to be and that they will not benefit from the Qur’an because they are steeped in arrogance and are stubbornly opposed to accepting and believing it.
Numerous indeed were the peoples before the unbelievers of the Quraysh that We destroyed because of their unbelief and denial of the truth! They cried out to Us to save them from the punishment when it descended upon them, but it was not a time to escape punishment by seeking repentance.