The Messenger of Allah ﷺ forbade that a man propose marriage over his brother's proposal, or that he negotiate a sale over his brother's sale.
أن رسول الله ﷺ نهي أن يخطب الرجل على خطبة أخيه، أو يبتاع على بيعه.
Ahmad (20115) narrated it from Sulayman bin Dawud Tayalisi, who said, Imran narrated to me, from Qatada, from Hasan, from Samura bin Jundab, and he mentioned it. Its chain is hasan because of Imran, who is Ibn Dawud Basri, about whom there is disagreement, but his hadith is hasan. Hasan heard from Samura in general, as previously mentioned.