Sunan Abi Dawud 2080
سنن أبي داود#2080Sahihحَدَّثَنَا 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 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.”
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautHasan Sahih
Zubair Ali ZaiSahih Bukhari (2140) Sahih Muslim (1413)
In-book reference: 12:35