بُلُوغُ الْمَرَامِ
Bulugh al-Maram 987
Marriage
وَعَنْ نَافِعٍ , عَنْ اِبْنِ عُمَرَ قَالَ : { نَهَى رَسُولُ اَللَّهِ - صلى الله عليه وسلم -عَنِ الشِّغَارِ ; وَالشِّغَارُ: أَنْ يُزَوِّجَ اَلرَّجُلُ اِبْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ اَلْآخَرُ اِبْنَتَهُ , وَلَيْسَ بَيْنَهُمَا صَدَاقٌ } مُتَّفَقٌ عَلَيْهِ [1] .
Narrated Nafi' from Ibn 'Umar (RA): Allah's Messenger (ﷺ) prohibited Shighar, which means that a man gives his daughter in marriage on condition that the other gives his daughter to him in marriage [in exchange] without any dowry being paid by either. [Agreed upon].
Sunnah.com reference: Book 8, Hadith 22