Al-Hāfidh Ibn Hajr (rahimahullāh) said:
وَعَنِ ابْنِ عَبَّاسٍ -رَضِيَ اللَّهُ عَنْهُمَا- قَالَ: تَزَوَّجَ النَّبِيُّ – صلى الله عليه وسلم – مَيْمُونَةَ وَهُوَ مُحْرِمٌ. مُتَّفَقٌ عَلَيْهِ.
صحيح. رواه البخاري (1837)، ومسلم (1410)
وَلِمُسْلِمٍ: عَنْ مَيْمُونَةَ نَفْسِهَا – أَنَّ النَّبِيَّ – صلى الله عليه وسلم – تَزَوَّجَهَا وَهُوَ حَلَالٌ
صحيح. رواه مسلم (1411)
993/994: Narrated Ibn ‘Abbās (radiyallaahu ‘anhu):
“The Prophet (salallaahu ‘alaihi wassallam) married Maymoonah whilst in a state of Ihraam.”
Agreed upon: Bukhaaree no. 1837; Muslim no. 1410. Muslim narrated from Maymoonah herself:
“The Prophet (salallaahu ‘alaihi wassallam) married her when he was out of ihraam.”
Muslim no. 1411.
Shaikh Sālih al-Fawzān (hafidhahullāh) said:
So after narrating the hadeeth [of ‘Uthmaan] which states: “The Muhrim may not marry or perform a marriage” he now mentions the hadeeth of Ibn Abbaas: “The Prophet (salallahu ‘alaihi wasallam) married Maymoonah whilst in a state of Ihraam.” This hadeeth seems apparently to contradict the previous hadeeth of ‘Uthmaan. However the second hadeeth is speculation and an error from Ibn Abbaas – and the proof is that Maymoonah herself informed us that he was out of ihraam – and she is the person under discussion here. Likewise, it is narrated from Abu Raafi’, and he was the mediator between the Messenger (salallaahu ‘alaihi wasallam) and Maymoonah; he also stated that the Messenger married Maymoonah and he was not in ihraam. This was reported by at-Tirmidhee in his al-Jaami’ (841) from Abu Raafi’ who said: “The Messenger (salallaahu ‘alaihi wasallam) married Maymoonah and he was not in ihraam. He married her and he was out of ihraam – and I was the messenger between the two of them.” So this indicates that the narration of Ibn ‘Abbaas (radiyallaahu ‘anhumaa) is a mistake even if the chain of narration is saheeh (authentic).
Furthermore, at that time [of the marriage] Ibn Abbaas was young, so it is as if he was not fully certain of the story – therefore the hadeeth is not acted upon.
If there appears a contradiction between two hadeeth whilst both are equal in terms of chain of narration, then weight should be given to the narration reported by the plenty over that which is reported by one person. That is because uncertainty and mistake is more likely with one person than with the many. So the majority all narrated that the Messenger (salallaahu ‘alahi wassallam) married Maymoonah whilst he was not in ihraam. And Ibn Abbaas narrated that he married her whilst in ihraam. And there is no doubt that one of the two reports in incorrect. The mistake being in the narration of Ibn Abbaas is more likely because it is a sole narration and the other narrations are narrated by a body of narrators. So a mistake in those narrations is more unlikely. See Siyar A’laam an-Nubalaa 2/238.
As for Maymoonah, then she is Maymoonah bint Al-Haarith Al-Hilaaliyah (radiyallaahu ‘anhaa); she was the aunt of Ibn Abbaas and the aunt of Khaalid Ibn Waleed (radiyallaahu ‘anhu).
Adapted from volume 4, page 304, Kitābun-Nikāh (The Book of Marriage) from Shaikh Sālih al-Fawzān’s explanation of Bulūgh Al-Marām min Adillatil-Ahkām of Al-Hāfidh Ahmad Ibn ‘Ali Ibn Hajr Al-Asqalāni (born 773H, died 852H), entitled Tas-heel al-Ilmām bi-fiqhil-Ahādeeth min Bulūghil-Marām and is printed in seven volumes.