وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ بِنَحْوِهِ وَفِيهِ وَأَمَّا الْبَيْعَتَانِ فَالْمُلَامَسَةُ أَلْقِ إِلَى وَأَلْقِ إِلَيْكَ وَإِلْقَاءُ الْحَجَرِ
A similar hadith is narrated from Sayyiduna Abu Hurairah, may Allah be pleased with him, in which it is mentioned: As for the matter of two trades, one is Mulamasah, and that is when they say to each other: You throw towards me and I throw towards you, and the second trade is throwing a stone.