16:65
وَٱللَّهُ أَنزَلَ مِنَ ٱلسَّمَآءِ مَآءًۭ فَأَحْيَا بِهِ ٱلْأَرْضَ بَعْدَ مَوْتِهَآ ۚ إِنَّ فِى ذَٰلِكَ لَءَايَةًۭ لِّقَوْمٍۢ يَسْمَعُونَ
And Allah has sent down rain from the sky and given life thereby to the earth after its lifelessness. Indeed in that is a sign for a people who listen.
Translation · Saheeh International
Tafsir
Ibn Kathīr (abridged)
Finding Consolation in the Reminder of Those Who came before
Allah says, `He sent Messengers to the nations of the past, and they were rejected. You, O Muhammad, have an example in your brothers among the Messengers, so do not be distressed by your people's rejection. As for the idolators' rejection of the Messengers, the reason for this is that the Shaytan made their deeds attractive to them.'
فَهُوَ وَلِيُّهُمُ الْيَوْمَ
(So today he (Shaytan) is their helper,) meaning they will be suffering punishment while Shaytan is their only helper, and he cannot save them, so they have no one to answer their calls for help, and theirs is a painful punishment.
The Reason why the Qur'an was revealed
Then Allah says to His Messenger that He has revealed the Book to him to explain the truth to mankind in matters which they dispute over. So the Qur'an is a decisive arbitrator for every issue that they argue about.