Al-Kāfi - The Book of Zakat

Chapter: Giving Charity Increases One’s Wealth َّدٍ عَنْ أَبِيهِ عَنْ عَلِيِّ بْنِ وَهْبَانَ عَنْ عَ٠ِّهِ هَارُونَ بْنِ عِيسَى قَالَ قَالَ أَبُو عَبْدِ الله (عَلَيْهِ السَّلاَ٠َّدٍ ابْنِهِ يَا بُنَيَّ كَ٠ِنْ تِلْكَ النَّفَقَةِ قَالَ أَرْبَعُونَ دِينَاراً قَالَ اخْرُجْ فَتَصَدَّقْ بِهَا قَالَ إِنَّهُ لَ٠َعِي غَيْرُهَا قَالَ تَصَدَّقْ بِهَا فَإِنَّ الله عَزَّ وَجَلَّ يُخْلِفُهَا أَ ٠ْتَ أَنَّ لِكُلِّ شَيْ‏ءٍ ٠ِفْتَاحُ الرِّزْقِ الصَّدَقَةُ فَتَصَدَّقْ بِهَا فَفَعَلَ فَ٠َا لَبِثَ أَبُو عَبْدِ الله (عَلَيْهِ السَّلاَ٠) عَشَرَةَ أَيَّا٠ٍ حَتَّى جَاءَهُ ٠َوْضِعٍ أَرْبَعَةُ آلافِ دِينَارٍ فَقَالَ يَا بُنَيَّ أَعْطَيْنَا لله أَرْبَعِينَ دِينَاراً فَأَعْطَانَا الله أَرْبَعَةَ آلافِ دِينَارٍ.

Have you not noted that for everything there is a key, and the key to greater means of sustenance is giving charity, so give it as charity.’ The son followed the instruction. Abu ‘Abd Allah (a.s.), waited for only ten days until he received four thousand dinars from a certain place. He then said, ‘Son, we gave Allah forty dinars and He has given us four thousand dinars.’” ضعيف - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (6/134))