Tafsir of Al-Ma'aarij 70:17

تَدْعُو مَنْ أَدْبَرَ‌ وَتَوَلَّىٰ وَجَمَعَ فَأَوْعَىٰ (It will call him who had turned his back and fled away (from the truth.) and accumulated (wealth) and hoarded (it)....70:17, 18). The phrase 'accumulated wealth' signifies 'wealth accumulated by unlawful means' and the phrase 'hoarded it' signifies 'not fulfilling the pecuniary obligations as imposed by the Shari` ah', as is confirmed by authentic ahadi'th.