The Reward of His Wives for choosing to stay with the Messenger
Allah says;
لَاا يَحِلُّ لَكَ النِّسَاء مِن بَعْدُ وَلَاا أَن تَبَدَّلَ بِهِنَّ مِنْ أَزْوَاجٍ وَلَوْ أَعْجَبَكَ حُسْنُهُنَّ إِلاَّ مَا مَلَكَتْ يَمِينُكَ وَكَانَ اللَّهُ عَلَى كُلِّ شَيْءٍ رَّقِيبًا
It is not lawful for you (to marry other) women after this, nor to change them for other wives even though their beauty attracts you, except those whom your right hand possesses. And Allah is Ever a Watcher over all things.
More than one of the scholars, such as Ibn Abbas, Mujahid, Ad-Dahhak, Qatadah, Ibn Zayd, Ibn Jarir and others stated that this Ayah was revealed as a reward to the wives of the Prophet expressing Allah's pleasure with them for their excellent decision in choosing Allah and His Messenger and the Home of the Hereafter, when the Messenger of Allah , gave them the choice, as we have stated above. When they chose the Messenger of Allah their reward was that Allah restricted him to these wives, and forbade him to marry anyone else or to change them for other wives, even if he was attracted by their beauty -- apart from slave-girls and prisoners of war, with regard to whom there was no sin on him.
Then Allah lifted the restriction stated in this Ayah and permitted him to marry more women, but he did not marry anyone else, so that the favor of the Messenger of Allah towards them would be clear.
Imam Ahmad recorded that A'ishah, may Allah be pleased with her, said;
"The Messenger of Allah did not die until Allah permitted (marriage to other) women for him."
It was also recorded by At-Tirmidhi and An-Nasa'i in their Sunans.
On the other hand, others said that what was meant by the Ayah,
لَاا يَحِلُّ لَكَ النِّسَاء مِن بَعْدُ
(It is not lawful for you (to marry other) women after this,
means, `after the description We have given of the women who are lawful for you, those to whom you have given their dowry, those whom your right hand possesses, and daughters of your paternal uncles and aunts, maternal uncles and aunts, and those who offer themselves to you in marriage -- other kinds of women are not lawful for you.'
This view was narrated from Ubayy bin Ka`b, from Mujahid in one report which was transmitted from him, and others.
At-Tirmidhi recorded that Ibn Abbas said;
"The Messenger of Allah was forbidden to marry certain kinds of women apart from believing women who had migrated with him, in the Ayah,
لَاا يَحِلُّ لَكَ النِّسَاء مِن بَعْدُ وَلَاا أَن تَبَدَّلَ بِهِنَّ مِنْ أَزْوَاجٍ وَلَوْ أَعْجَبَكَ حُسْنُهُنَّ إِلاَّ مَا مَلَكَتْ يَمِينُك
It is not lawful for you (to marry other) women after this, nor to change them for other wives even though their beauty attracts you, except those whom your right hand possesses.
Allah has made lawful believing women, and believing women who offered themselves to the Prophet for marriage, and He made unlawful every woman who followed a religion other than Islam, as Allah says;
وَمَن يَكْفُرْ بِالاِيمَـنِ فَقَدْ حَبِطَ عَمَلُهُ
And whosoever disbelieves in faith, then fruitless is his work. (5;5)
Ibn Jarir, may Allah have mercy on him, stated that this Ayah is general in meaning and applies to all the kinds of women mentioned and the women to whom he was married, who were nine.
What he said is good, and may be what many of the Salaf meant, for many of them narrated both views from him, and there is no contradiction between the two. And Allah knows best.
وَلَا أَن تَبَدَّلَ بِهِنَّ مِنْ أَزْوَاجٍ وَلَوْ أَعْجَبَكَ حُسْنُهُنَّ
nor to change them for other wives even though their beauty attracts you,
He was forbidden to marry more women, even if he were to divorce any of them and wanted replace her with another, except for those whom his right hand possessed (slave women)