Surah Al-Baqarah (The Cow), Verse 74

ثُمَّ قَسَتْ قُلُوْبُكُمْ مِّنْ بَعْدِ ذٰلِكَ فَهِیَ كَالْحِجَارَةِ اَوْ اَشَدُّ قَسْوَةً وَاِنَّ مِنَ الْحِجَارَةِ لَمَا یَتَفَجَّرُ مِنْهُ الْاَنْهٰرُ وَاِنَّ مِنْهَا لَمَا یَشَّقَّقُ فَیَخْرُجُ مِنْهُ الْمَآءُ وَاِنَّ مِنْهَا لَمَا یَهْبِطُ مِنْ خَشْیَةِ اللّٰهِ وَمَا اللّٰهُ بِغَافِلٍ عَمَّا تَعْمَلُوْنَ ۟

Summa qasat quloobukum mim ba'di zaalika fahiya kalhijaarati aw-ashaadu qaswah; wa inna minal hijaarati lamaa yatafajjaru minhul anhaar; wa inna minhaa lamaa yash shaqqaqu fayakhruju minhul maaa'; wa inna minhaa lamaa yahbitu min khashyatil laa; wa mal laahu bighaafilin 'ammaa ta'maloon

“Thenceforth were your hearts hardened: They became like a rock and even worse in hardness. For among rocks there are some from which rivers gush forth; others there are which when split asunder send forth water; and others which sink for fear of Allah. And Allah is not unmindful of what ye do.”

Quran 2:74 (Yusuf Ali Translation)