Surah Al-'Adiyat, Ayah 10

Which was revealed in Makkah

بِسْمِ اللَّهِ الرَّحْمَـنِ الرَّحِيمِ

(In the Name of Allah, the Most Gracious, the Most Merciful.

Swearing by the Horses of War about the Ungratefulness of Man and His Zeal for Wealth

Allah swears by the horses when they are made to gallop into battle in His path (i.e., Jihad), and thus they run and pant, which is the sound that is heard from the horse when it runs.

فَالمُورِيَـتِ قَدْحاً

(Striking sparks of fire.) meaning, the striking of their hooves on the rocks, which causes sparks of fire to fly from them.

فَالْمُغِيرَتِ صُبْحاً

(And scouring to the raid at dawn.) meaning, the raid that is carried out in the early morning time. This is just as the Messenger of Allah ﷺ used to perform raids in the early morning. He would wait to see if he heard the Adhan (call to prayer) from the people. If he heard it he would leave them alone, and if he didn't hear it he would attack. Then Allah says,

Verses [ 100:9-11] وَحُصِّلَ مَا فِي الصُّدُورِ‌ ﴿10﴾ إِنَّ رَ‌بَّهُم بِهِمْ يَوْمَئِذٍ لَّخَبِيرٌ‌ ﴿11﴾ أَفَلَا يَعْلَمُ إِذَا بُعْثِرَ‌ مَا فِي الْقُبُورِ‌ ﴿9﴾ (Does he not then know [ what will happen ] when all that is contained in the graves will be overturned, and all that is contained in the hearts will be exposed. Surely your Lord, that day, is fully aware of them.) Divine retribution will be meted out, in the Hereafter, to each person commensurate with his deeds, good or bad, as Allah is well-aware of them. Therefore, it would be wise for man to abstain from ingratitude, and he should not have such a violently passionate love for wealth and indulgence in worldly riches as to be unable to separate the good from the bad.