Nahj al-Balāgha
Hadith 1266وَإِنِّي أُقْسِمُ بِاللهِ قَسَماً صَادِقاً، لَئِنْ بَلَغَني أَنَّكَ خُنْتَ مِنْ فَيْءِ الْمُسْلِمِينَ شَيْئاً صَغِيراً أَوْ كَبِيراً، لَأَشُدَّنَّ عَلَيْكَ شَدَّةً تَدَعُكَ قَلِيلَ الْوَفْرِ، ثَقِيلَ الظَّهْرِ، ضَئِيلَ الْأَمْرِ، وَالسَّلَامُ.
I truthfully swear by Allāh that if I come to know that you have misappropriated the funds of the Muslims, small or big, I shall inflict upon you such punishment which will leave you empty handed, heavy backed and humiliated; and that is an end to the matter.