When you have stopped being affected by anything
A description of hearts that hardened after having been given the truth.
۞ 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 ٱعْلَمُوٓا۟ أَنَّ ٱللَّهَ يُحْىِ ٱلْأَرْضَ بَعْدَ مَوْتِهَا ۚ قَدْ بَيَّنَّا لَكُمُ ٱلْـَٔايَـٰتِ لَعَلَّكُمْ تَعْقِلُونَ
…wa lā yakūnū ka-lladhīna ūtu-l-kitāba min qablu fa-ṭāla ʿalayhimu-l-amadu fa-qasat qulūbuhum… iʿlamū anna-llāha yuḥyi-l-arḍa baʿda mawtihā.
“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. Know that Allāh gives life to the earth after its lifelessness. We have made clear to you the signs; perhaps you will understand.1”
The consolation is put immediately after the warning: what has died can be brought back.
Source
The Qur'an · 57:16-17
- Qur'anic text in the Uthmani script via Quran.com; translation: Saheeh International