That the Messenger of Allah ﷺ said: "None of you is to sell over the sale of others, nor to propose over the proposal of others." [He said:] There are narration on this topic from Abu Hurairah and Samurah.  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَبِيعُ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ وَلاَ يَخْطُبُ بَعْضُكُمْ عَلَى خِطْبَةِ بَعْضٍ قَالَ وَفِي الْبَابِ عَنْ أَبِي هُرَيْرَةَ وَسَمُرَةَ