(18) باب فِي كَرَاهِيَةِ أَنْ يَخْطُبَ 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."
Reference: Sunan Abi Dawud 2080
In-book reference: Book 12, Hadith 35
English translation: Book 11, Hadith 2075