سُنَنُ أَبِي دَاوُدَ
Sunan Abi Dawud 2080
Marriage (Kitab Al-Nikah)
Regarding it being disliked for a person to propose after his brother's proposal
حَدَّثَنَا أَحْمَدُ بْنُ عَمْرِو بْنِ السَّرْحِ، حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم لاَ يَخْطُبُ الرَّجُلُ عَلَى خِطْبَةِ أَخِيهِ .
Abu Hurairah reported the Messenger 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.”
Sunan Abi Dawud, 2080Sahih (Al-Albani)صحيح (الألباني)