Hadith 3339
It was narrated from Ibn 'Umar that the Messenger of Allah forbade Ash-Shighar. Ash-Shighar means when a man marries his daughter to another man, on the condition that that man marries his daughter to him, and no dowry is exchanged between them.
Hadith 3340
´It was narrated that Abu Hurairah said:` "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."