Hawzah News Agency – Imam al-Baqir peace be upon him says:

إنَّ للَّهِ عُقوباتٍ في القُلوبِ والأبدانِ :ضَنْكٌ في المَعيشَةِ ووَهنٌ في العِبادَةِ، وما ضُرِبَ عَبدٌ بِعُقوبَةٍ أعظَمَ مِن قَسوَةِ القَلبِ.

'Allah has punishments of the hearts and of the bodies: a difficult livelihood, weakness in worship, and the harshest punishment a servant is stricken with is hardness of the heart.'

Source: Tuhaf al-Uqul, no. 296