A question asked gently, and it stings
Revealed to believers, not to disbelievers.
۞ أَلَمْ يَأْنِ لِلَّذِينَ ءَامَنُوٓا۟ أَن تَخْشَعَ قُلُوبُهُمْ لِذِكْرِ ٱللَّهِ وَمَا نَزَلَ مِنَ ٱلْحَقِّ وَلَا يَكُونُوا۟ كَٱلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ مِن قَبْلُ فَطَالَ عَلَيْهِمُ ٱلْأَمَدُ فَقَسَتْ قُلُوبُهُمْ ۖ وَكَثِيرٌ مِّنْهُمْ فَـٰسِقُونَ
A-lam ya'ni li-lladhīna āmanū an takhshaʿa qulūbuhum li-dhikri-llāh…
“Has the time not come for those who have believed that their hearts should become humbly submissive at the remembrance of Allāh and what has come down of the truth? And let them not be like those who were given the Scripture before, and a long period passed over them, so their hearts hardened; and many of them are defiantly disobedient.”
Where this comes from
Ibn Masʿūd said that only four years passed between their becoming Muslim and this verse being revealed to correct them.
Source
The Qur'an · 57:16
- Qur'anic text in the Uthmani script via Quran.com; translation: Saheeh International