Hadithcore
Mishkat al-Masabih, 2936

Suhaib reported God's Messenger as saying, “There are three things which contain blessing:

A business transaction with a time specified, muqarada* and mixing wheat and barley for one’s household but not for sale.” Ibn Majah transmitted it. * Giving someone some property to trade with, the profit being shared between the two, but any loss falling on the property.

عَن صُهَيْبٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ:

ثَلَاثٌ فِيهِنَّ الْبَرَكَةُ: الْبَيْعُ إِلَى أَجَلٍ والمقارضة واخلاط الْبُرِّ بِالشَّعِيرِ لِلْبَيْتِ لَا لِلْبَيْعِ

. رَوَاهُ ابْنُ مَاجَه

References1 variant
In-Book Reference
Book 11, Hadith 172