ثُمَّ قَسَتۡ قُلُوبُكُم مِّنۢ بَعۡدِ ذَٰلِكَ فَهِيَ كَٱلۡحِجَارَةِ أَوۡ أَشَدُّ قَسۡوَةٗۚ وَإِنَّ مِنَ ٱلۡحِجَارَةِ لَمَا يَتَفَجَّرُ مِنۡهُ ٱلۡأَنۡهَٰرُۚ وَإِنَّ مِنۡهَا لَمَا يَشَّقَّقُ فَيَخۡرُجُ مِنۡهُ ٱلۡمَآءُۚ وَإِنَّ مِنۡهَا لَمَا يَهۡبِطُ مِنۡ خَشۡيَةِ ٱللَّهِۗ وَمَا ٱللَّهُ بِغَٰفِلٍ عَمَّا تَعۡمَلُونَ

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.

— Al-Baqarah (ٱلْبَقَرَة), 2:74