Hadith 1414
وَحَدَّثَنِي أَبُو الطَّاهِرِ، أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، عَنِ اللَّيْثِ، وَغَيْرِهِ، عَنْ يَزِيدَ بْنِ، أَبِي حَبِيبٍ عَنْ عَبْدِ الرَّحْمَنِ بْنِ شُمَاسَةَ، أَنَّهُ سَمِعَ عُقْبَةَ بْنَ عَامِرٍ، عَلَى الْمِنْبَرِ يَقُولُ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " الْمُؤْمِنُ أَخُو الْمُؤْمِنِ فَلاَ يَحِلُّ لِلْمُؤْمِنِ أَنْ يَبْتَاعَ عَلَى بَيْعِ أَخِيهِ وَلاَ يَخْطُبَ عَلَى خِطْبَةِ أَخِيهِ حَتَّى يَذَرَ " .
'Uqba b. 'Amir said on the pulpit that Allah's Messenger (ﷺ) said:
A believer is the brother of a believer, so it is not lawful for a believer to outbid his brother, and he should not propose an engagement when his brother has thus proposed until he gives it up.
Reference : Sahih Muslim 1414
In-book reference : Book 16, Hadith 66
USC-MSA web (English) reference : Book 8, Hadith 3294