Following is the article by Muhammad Kashif Khan regarding conditional divorce.
The issue of Conditional Divorce
The Scholars are divided on this issue into three categories :
1. Majority of the Scholars agree that this kind of divorce takes place.
2. If the Husband intends to divorce it does take place otherwise it doesn’t if he just places the condition to just prevent her wife from doing something or etc but he has to pay Kuffarra Yameen for it. This view held by Ibn e Taimiya and his student Ibn Qayyam.
3. It is null and void because there is no clear proof in the Quran and Sunnah that it takes place this view was held by some of the Salaf such as Tawus etc, Ibn Hazm, Some of the Shafaes, and also held by contemporary Salafi Scholars such as Sh Mustufa Al Adwi and Sh Amr bin Abdul Munim.
The third view is the correct and closest to Quran and Sunnah because there is no proof in the Quran and Sunnah that such kind of divorce takes place.
I only mentioned some of the proofs over this issue for details you can read the details elucidated by Ibn Hazm in Muhalla, Sh Amr bin Abdul Munim in his Kitab ul Talaaq etc.
Allah swt says in the Quran :
O Prophet (Muhammad )! Say to your wives: If you desire the life of this world, and its glitter, Then come! I will make a provision for you and set you free in a handsome manner (divorce) (Surah Al Ahzab 28)
Ibn Hazm concluded from this ayah that the second matter i.e divorce was given back in the hands of Husband i.e RasulAllah saw and was not left upon for the wives of Prophet.
Similarly in one of authentic the narrations which Abu Bakr Al Asram reported in his Sunan :
Laila bint Al Ajma said all of my slaves will be free, and all of my money will be in charity If such and such man doesn’t divorces his wife.
So she conditioned a thing with a condition. After it she inquired about it from the Companions of Prophet saw.
She asked Zainab r.a about it and she replied : Fear Allah and pay expiation from your right hand and get away from the way of this Man and His Wife (While Zainab r.a didn’t ask for the intention.)
Similar is stated by Hafsa r.a to her, Then she went to Ibn Umar and asked him to which he replied :
Are you made up of steel or of copper?
Zainab and Umm ul Momineem Hafsa issued you a Fatwa already.
Ibn Umar r.a also said to her : Fear Allah and give expiation from your right hand and also leave the way of this man and his wife.
See [Majmoa al Fatawa الفقه » الطلاق » باب الحلف بالطلاق وغير ذلك » مسألة حلف بالطلاق على أمر من الأمور ثم حنث في يمينه]
If freeing a slave doesn’t occur by placing a condition, then Talaq which is more important than just freeing a slave doesnt occur as well.
Ibn Tawus reported with an authentic chain from Tawus Tabae that Condition Divorce is null and void , i said do you see expiation yameen over it? He said I don’t know.[Al Muhalla 6/478.]
Ibn Al Qayyam quoted the Salaf who held this view such as Ikrimah, Shari Qazi Syedna Ali, Ibn Masud, Dawud bin Ali and his Companions and some of the Companions of Malik.
(Ilam al Muaqeen 3/89)