The Messenger of Allah ﷺ forbade shighar marriage.Ibn Numayr added, "Shighar is when a man says to another, 'Marry me your daughter and I will marry you my daughter,' or, 'Marry me your sister and I will marry you my sister.'"
نهى رسول الله ﷺ عن الشغار. زاد ابن نمير: والشغار أن يقول الرجل للرجل: زوجني ابنتك، وأزوجك ابنتي، أو زوجني أختك، وأزوجك أختي.
Muslim narrated it in the Book of Marriage (1416) from Abu Bakr bin Abu Shayba, who said, "Ibn Numayr and Abu Usama narrated to us, from Ubaydullah, from Abu Zinad, from Araj, from Abu Hurairah," and he related it.Nasai narrated it (3338) through another route from Ubaydullah with his chain, and in it Ubaydullah said, "Shighar was when a man would marry off his daughter on condition that the other man marry him his sister." This makes clear that this explanation comes from Ubaydullah himself, and it is not part of what is attributed to the Prophet, nor is it the statement of the companion.Qurtubi did not come across this, for he said in Mufhim (112/4), "The explanation of shighar has come in the hadith of Ibn Umar as the statement of Nafi, and it has come in the hadith of Abu Hurairah as part of the words of the Messenger of Allah ﷺ, and in its wording and apparent sense it is elevated to the Prophet ﷺ. It is possible that it is from the explanation of Abu Hurairah, or of another of the narrators, meaning in the hadith of Abu Hurairah. Whatever the case, it is a sahih explanation, in agreement with what the people of language have related. If it is the statement of the Messenger of Allah ﷺ, then that is what is intended, and if it is the statement of a companion, then it is accepted, for they had greater knowledge of the wording and were better placed regarding the situation."As for the statements of the scholars concerning the ruling on shighar marriage, see Minna Kubra (190/6-191).