Sahih Muslim Book - 16, Hadith - 3465

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ نَافِعٍ عَنِ ابْنِ عُمَرَ أَنَّ رَسُولَ اللَّهِ -صلى الله عليه وسلم- نَهَى عَنِ الشِّغَارِ. وَالشِّغَارُ أَنْ يُزَوِّجَ الرَّجُلُ ابْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ ابْنَتَهُ وَلَيْسَ بَيْنَهُمَا صَدَاقٌ.

It was narrated from Ibn 'Umar that the Messenger of Allah (s.a.w) forbade Shighar marriage. Shighar is when a man gives his daughter in marriage to another man in return for marrying the latter's daughter, with no dowry given.