(7) باب تَحْرِيمِ نِكَاحِ الشِّغَارِ وَبُطْلاَنِهِ
Ibn Umar (Allah be pleased with them) said that Allah's Messenger (ﷺ) prohibited Shighar which means that a man gives his daughter in marriage on the condition that the other gives his daughter to him in marriage with- out any dower being paid by either.
Reference: Sahih Muslim 1415 a
In-book reference: Book 16, Hadith 67
USC-MSA web (English) reference(deprecated numbering scheme): Book 8, Hadith 3295