He heard Uqba bin Amir saying from the pulpit, "The Messenger of Allah ﷺ said, 'The believer is the brother of the believer. It is not lawful for a believer to buy over his brother's purchase, nor to propose marriage over his brother's proposal until he withdraws.'"
أنه سمع عقبة بن عامر على المنبر يقول: إن رسول الله ﷺ قال: المؤمن أخو المؤمن؛ فلا يحل للمؤمن أن يبتاع على بيع أخيه، ولا يخطب على خطبة أخيه حتى يذر.
Muslim narrated it in the Book of Marriage (1414:56), from Abu Tahir, who said, Abdullah bin Wahb informed us, from Layth and others, from Yazid bin Abu Habib, from Abdul-Rahman bin Sahammasa, and he mentioned it.