"The Messenger of Allah forbade Ash-Shighar." (One of the narrators) 'Ubaidullah said: "Ash-Shighar means when a man gives his daughter in marriage on condition that (the other man) gives him his sister in marriage."
نَهَى رَسُولُ اللَّهِ ﷺ عَنِ الشِّغَارِ قَالَ عُبَيْدُ اللَّهِ وَالشِّغَارُ كَانَ الرَّجُلُ يُزَوِّجُ ابْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ أُخْتَهُ
Yahya related to me from Malik from Nafi from Abdullah ibn Umar that the Messenger of Allah ﷺ forbade shighar, which meant one man giving his daughter in marriage to another man on the condition that the other gave his daughter to him in marriage without either of them paying the bride-price.
أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنِ الشِّغَارِ وَالشِّغَارُ أَنْ يُزَوِّجَ الرَّجُلُ ابْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ الآخَرُ ابْنَتَهُ لَيْسَ بَيْنَهُمَا صَدَاقٌ