None amongst you should outbid another in a transaction, nor should he make proposals of marriage upon the proposal made by someone else.
Sahih Muslim Book 16, Hadith 57
← Previous Hadith Maimuna daughter of al-Harith narrated to me that Allah's Messenger (ﷺ) married her and he was not in the state of Ihram. And she (Maimuna) was my mother's sister and that of Ibn 'Abbas (Allah be pleased with them).

Sahih Muslim Book 16, Hadith 56 Next Hadith → A person should not enter into a transaction when his brother (had already entered into but not finalised), and he should not make proposal of marriage upon the proposal already made by his brother, until he permits it.

Sahih Muslim Book 16, Hadith 58