Abu Hurairah reported the Apostle of Allaah ﷺ as saying “ A man should not seek the hand of a woman in marriage when his brother has already sought her hand.”  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَخْطُبُ الرَّجُلُ عَلَى خِطْبَةِ أَخِيهِ  

The Prophet ﷺ said: One of you must not ask a woman in marriage when his brother has done so already, and one of you must not sell (his own goods) when his brother has already sold (his goods) except with his permission.  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَخْطُبُ أَحَدُكُمْ عَلَى خِطْبَةِ أَخِيهِ وَلاَ يَبِيعُ عَلَى بَيْعِ أَخِيهِ إِلاَّ بِإِذْنِهِ