حَدَّثَنَا يَحْيَى عَنْ عُبَيْدِ اللَّهِ حَدَّثَنِي نَافِعٌ عَنِ ابْنِ عُمَرَ عَنْ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ لَا يَبِعْ أَحَدُكُمْ عَلَى بَيْعِ أَخِيهِ وَلَا يَخْطُبْ عَلَى خِطْبَةِ أَخِيهِ إِلَّا أَنْ يَأْذَنَ لَهُ
مسند امام احمد بن حنبل · Hadith 4722
It was narrated from Ibn 'Umar from the Prophet (PBUH): "No one among you should outbid or undersell) his brother, nor should he propose marriage when his brother has already proposed, unless he gives him permission.
Sanad
حَدَّثَنَا يَحْيَى عَنْ عُبَيْدِ اللَّهِ حَدَّثَنِي نَافِعٌ عَنِ ابْنِ عُمَرَ