وعن ابن عمر رضي الله عنهما
أن رسول الله صلى الله عليه وسلم قال: «لا يبع بعضكم على بيع بعض، ولا يخطب على خطبة أخيه إلا أن يأذن له»
The Messenger of Allah (sallallahu alayhi wa sallam) said, “A person should not enter into a transaction when his (Muslim) brother has already negotiated, nor should he make a proposal of marriage when that of his brother is pending, except with the permission of the latter.”
Riyad as-Salihin 1779, Book 18, The Book of the Prohibited actions, Hadith 269. 1 min read