Stones

ثُمَّ قَسَتْ قُلُوبُكُم مِّن بَعْدِ ذَلِكَ فَهِيَ كَالْحِجَارَةِ أَوْ أَشَدُّ قَسْوَةً وَإِنَّ مِنَ الْحِجَارَةِ لَمَا يَتَفَجَّرُ مِنْهُ الأَنْهَارُ وَإِنَّ مِنْهَا لَمَا يَشَّقَّقُ فَيَخْرُجُ مِنْهُ الْمَاء وَإِنَّ مِنْهَا لَمَا يَهْبِطُ مِنْ خَشْيَةِ اللّهِ وَمَا اللّهُ بِغَافِلٍ عَمَّا تَعْمَلُونَ
Then, even after that, your hearts were hardened and became as stones, or worse than stones, for hardness. For indeed there are stones, from out which rivers gush, and indeed there are stones which split asunder so that water flows from them. And indeed there are stones which fall down for the fear of Allah. Allah is not unaware of what you do. [Surah Baqarah, verse 74]

This verse talks about 4 different types of stones, or rocks. Our hearts that become as hard as stones, stones from which rivers gush forth, stones which split and water flows from them and stones that fall from the fear of Allah.

Why does Allah (swt) mention our hearts in this verse, along with the stones?

Al-Qurtubi and other Imams say that Allah creates this characteristic - humbleness - in stones. Another view is that solid inanimate objects possess a certain degree of awareness.

Sometimes, even a stone can put you to shame.