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 .‏‏1 ‏- صحيح .‏ رواه البخاري ( 5112 )‏ ، ومسلم (1415)‏.‏
Translation
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].