Punishment of not paying Zakat
Thawāb al-Aʿmāl wa ʿiqāb al-Aʿmāl|Volume 1|Book 3|Chapter 42
وَ ذُکِرَ أَنَّ فِی رِوَایَهِ أَبِی بَصِیرٍ عَنْ أَبِی عَبْدِ اللَّهِ ع- مَنْ مَنَعَ الزَّکَاهَ فَلْیَمُتْ إِنْ شَاءَ یَهُودِیّاً أَوْ نَصْرَانِیّاً.
7. Imam Ja’far Sadiq عليه السلام said, “One who does not pay Zakat throughout his life, will desire to return to this world at the time of his death. One who avoids payment of a penny of Zakat and he dies, he has an option i.e. to die as a Jew or as a Christian.”