Whosoever employed a labourer (and after completing the work) the labourer left the wages and went away. The employer invested that money in some way and increased it thereby, or whoever invested somebody else’s money in business and increased it thereby.

Sahih al-Bukhari · Book 37 · Hadith 2272

حَدَّثَنَا أَبُو الْيَمَانِ، أَخْبَرَنَا شُعَيْبٌ، عَنِ الزُّهْرِيِّ، حَدَّثَنِي سَالِمُ بْنُ عَبْدِ اللَّهِ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ ـ رضى الله عنهما ـ قَالَ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ انْطَلَقَ ثَلاَثَةُ رَهْطٍ مِمَّنْ كَانَ قَبْلَكُمْ حَتَّى أَوَوُا الْمَبِيتَ إِلَى غَارٍ فَدَخَلُوهُ، فَانْحَدَرَتْ صَخْرَةٌ مِنَ الْجَ…

Narrated `Abdullah bin `Umar: I heard Allah's Messenger (ﷺ) saying, "Three men from among those who were before you, set out together till they reached a cave at night and entered it. A big rock rolled down the mountain…