Ar-Ra'd, "The Thunder," is the thirteenth surah — 43 verses.1 The standard Mushaf classes it as Medinan, but its place of revelation is disputed, and many commentators hold that its style and concerns are those of the Meccan period. It takes its name from a single striking image: "the thunder exalts [Allah] with praise of Him — and the angels [as well] from fear of Him."4
What it is about
The surah answers people who keep asking, "Why has a sign not been sent down to him from his Lord?" Its reply is that the signs are already overhead and underfoot. God "erected the heavens without pillars that you [can] see," set the sun and moon on their courses, spread the earth and placed mountains and rivers in it; and on neighboring plots "watered with one water," some fruit is made better than others.2 The surah sets this order against the idols its listeners call on, who answer them no more than water answers someone stretching a hand toward it from far away.
Key themes
Truth and falsehood. The surah's central parable compares revelation to rain: valleys fill "according to their capacity," and the torrent carries foam on its surface. So too metal heated for ornaments throws up scum. "As for the foam, it vanishes, [being] cast off; but as for that which benefits the people, it remains on the earth."5
People change their own condition. "Indeed, Allah will not change the condition of a people until they change what is in themselves."3 It is one of the most often quoted verses of the Quran, and it echoes a principle stated earlier in Al-Anfal.
The people of understanding. The surah describes them in a sequence: those who keep God's covenant, join the ties God ordered joined, are patient seeking His face, pray, spend in secret and openly, "and prevent evil with good." To them the angels will say, "Peace be upon you for what you patiently endured."6
Rest for the heart. At its center stands one of the Quran's most beloved verses: "Unquestionably, by the remembrance of Allah hearts are assured."7
God's decree. "Allah eliminates what He wills or confirms, and with Him is the Mother of the Book" — the source from which all revelation and decree proceed.8
Why it matters
Ar-Ra'd is a short surah that has given Muslims several of their most quoted verses: 13:11 on changing oneself before expecting change, 13:28 on the heart finding rest in remembrance of God, and the foam parable of 13:17, a classic image of how falsehood looks imposing and then disappears. To read Ar-Ra'd in Arabic with translations and recitation, open it on Quran.com.