He reported God’s Messenger as saying, “One must not offer more than the amount agreed by his brother*, or ask a woman in marriage when his brother has done so, unless he permits him.” *i.e. when the parties have already agreed on a price. Muslim transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب البيوع / 2850
Hadith Gradingالألبانی:صَحِيحٌ | زبیر علی زئی:صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «رواه مسلم (1412/50)»