Hadith 1376B1

قَالَ مَالِك : وَالْمُلَامَسَةُ : أَنْ يَلْمِسَ الرَّجُلُ الثَّوْبَ وَلَا يَنْشُرُهُ وَلَا يَتَبَيَّنُ مَا فِيهِ أَوْ يَبْتَاعَهُ لَيْلًا وَلَا يَعْلَمُ مَا فِيهِ . وَالْمُنَابَذَةُ : أَنْ يَنْبِذَ الرَّجُلُ إِلَى الرَّجُلِ ثَوْبَهُ وَيَنْبِذَ الْآخَرُ إِلَيْهِ ثَوْبَهُ عَلَى غَيْرِ تَأَمُّلٍ مِنْهُمَا، وَيَقُولُ كُلُّ وَاحِدٍ مِنْهُمَا : هَذَا بِهَذَا، فَهَذَا الَّذِي نُهِيَ عَنْهُ مِنَ الْمُلَامَسَةِ وَالْمُنَابَذَةِ .
Imam Malik, may Allah have mercy on him, said that "Mulamasa" is when a man buys a cloth by touching it, without unfolding it or looking inside, or buys it in the darkness of night, not knowing what is in it. And "Munabadhah" is when the seller throws his cloth towards the buyer, and the buyer throws his cloth towards the seller, without any thought or consideration; this one in exchange for that, and that one in exchange for this. Both of these are prohibited.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب البيوع / 1376B1
Hadith Takhrij «فواد عبدالباقي نمبر: 31 - كِتَابُ الْبُيُوعِ-ح: 76»