Ibn Umar (Allah be pleased with them) said that Messenger of Allah ﷺ prohibited Shighar which means that a man gives his daughter in marriage on the condition that the other gives his daughter to him in marriage with- out any dower being paid by either.  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنِ الشِّغَارِ وَالشِّغَارُ أَنْ يُزَوِّجَ الرَّجُلُ ابْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ ابْنَتَهُ وَلَيْسَ بَيْنَهُمَا صَدَاقٌ  

Shighar means that a person should say to the other person: Give me the hand of your daughter in marriage and I will (in return) marry my daughter to you; or merry me your sister, and I will marry my sister to you.  

نَهَى رَسُولُ اللَّهِ ﷺ عَنِ الشِّغَارِ زَادَ ابْنُ نُمَيْرٍ وَالشِّغَارُ أَنْ يَقُولَ الرَّجُلُ لِلرَّجُلِ زَوِّجْنِي ابْنَتَكَ وَأُزَوِّجُكَ ابْنَتِي أَوْ زَوِّجْنِي أُخْتَكَ وَأُزَوِّجُكَ أُخْتِي  

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.  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنِ الشِّغَارِ وَالشِّغَارُ أَنْ يُزَوِّجَ الرَّجُلُ الرَّجُلَ ابْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ ابْنَتَهُ وَلَيْسَ بَيْنَهُمَا صَدَاقٌ  

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  

[Machine] The Messenger of Allah ﷺ forbade equal treatment in marriage. He said, "Equal treatment is when a man says, 'Marry your daughter to me, and I will marry my daughter to you.' Or 'Marry your sister to me, and I will marry my sister to you.'" He also forbade the transaction of al-gharar (uncertainty) and al-hasah (the sale of stones used for weights).  

نَهَى رَسُولُ اللهِ ﷺ عَنِ الشِّغَارِ قَالَ وَالشِّغَارُ أَنْ يَقُولَ الرَّجُلُ زَوِّجْنِي ابْنَتَكَ وَأُزَوِّجُكَ ابْنَتِي أَوْ زَوِّجْنِي أُخْتَكَ وَأُزَوِّجُكَ أُخْتِي قَالَ وَنَهَى عَنْ بَيْعِ الْغَرَرِ وَعَنِ الْحَصَاةِ  

Ibn Umar said: “The Messenger of Allah forbade Shighar. Shighar is when a man says to another man: 'Marry your daughter or sister to me, on condition that I will marry my daughter or sister to you,' and they do not give any dower (i.e. neither of them give other the dower).” (Using translation from Ibn Mājah 1883)   

نَهَى رَسُولُ اللهِ ﷺ عَنِ الشِّغَارِ وَالشِّغَارُ أَنْ يَقُولَ الرَّجُلُ لِلرَّجُلِ زَوِّجْنِي ابْنَتَكَ وَأُزَوِّجُكَ ابْنَتِي أَوْ زَوِّجْنِي أُخْتَكَ وَأُزَوِّجُكَ أُخْتِي قَالَ وَنَهَى عَنْ بَيْعِ الْغَرَرِ وَعَنِ الْحَصَاةِ  

Messenger of Allah ﷺ forbade Ash-Shighar, which means that somebody marries his daughter to somebody else, and the latter marries his daughter to the former without paying Mahr. (Using translation from Bukhārī 5112)  

أَنَّ رَسُولَ اللهِ ﷺ «نَهَى عَنِ الشِّغَارِ وَالشِّغَارُ أَنْ يُزَوِّجَ الرَّجُلُ الرَّجُلَ ابْنَتَهُ عَلَى أَنْ يُزَوِّجَهُ ابْنَتَهُ وَلَيْسَ بَيْنَهُمَا صَدَاقٌ»