All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The report about Ibn ‘Umar was presented in Al-Bukhari as a Mu‘allaq report (whose chains of narrators are omitted) on the authority of Naafi‘ under the heading "Chapter: A divorce pronounced in a state of anger, under compulsion or under the effect of intoxicants or insanity." He cited in that chapter a report on the authority of Naafi‘ that a man said to his wife, "If you leave the house, you are divorced." When Ibn ‘Umar was asked about it, he said, "If she leaves the house, then she is divorced; and if she does not leave, nothing will happen."
Scholars explained that when Al-Bukhari cites a Mu‘allaq report using the active voice reporting verb (e.g. said), its chain of narration is considered authentic up to the very reporter he mentioned in the chain of narration, and the rest of the chain should be investigated before declaring its authenticity. In this case, the report was narrated on the authority of Naafi‘ from Ibn ‘Umar, which is one of the strongest (most authentic) chains of narration.
As for the report of Ibn Mas‘ood it was cited by Al-Bayhaqi in his book As-Sunan Al-Kubra. Hadeeth scholars classified this report as Munqati‘ (disconnected) because Ibraaheem who narrated it on the authority of Ibn Mas‘ood was the son of Yazeed An-Nakha‘i, and he was born seventeen years after the death of Ibn Mas‘ood.
The third narration was also cited by Al-Bayhaqi in his book As-Sunan Al-Kubra. Some scholars classified it as weak because it was narrated on the authority of Ismaa‘eel ibn Abi Uways; some scholars said he is a weak narrator.
Ibn Taymiyyah and his student Ibn Al-Qayyim relied on some accounts reported on the authority of our righteous predecessors to support their view that conditional divorce does not take effect if it was uttered merely for the purpose of threatening. For instance, it has been reported on the authority of Ibn ‘Umar, ‘Aa’ishah, and Umm Salamah that they all agreed that only expiation of breaking an oath was due in the famous incident when Layla bint Al-‘Ajmaa’ said (to her slave Abu Raafi‘), "If you do not divorce your wife, every slave owned by me is (to be) freed, every item of wealth owned by me is (to be) offered in charity, and I am (to be) considered a Jew or Christian!" They (Ibn Taymiyyah and Ibn Al-Qayyim) interpreted the reports that support the opposing opinion as pertaining to cases when the husband has the intention of divorce, thus adopting the methodology of resolving this narration and the other narrations that seemingly contradict it.
In any case, we are not concerned with detailing and discussing the issue of conditional divorce in this Fatwa; the Council of Senior Scholars has discussed this issue in detail and declared the opinion of the majority of scholars as the most valid opinion; and this is the opinion we adopt at Islamweb.
The last report of Ibn ‘Umar is related to the case when the husband authorizes his wife to issue the divorce. It is presented in Imaam Maalik's book Al-Muwatta’ under the heading "Cases when divorce takes effect when the wife is authorized (by the husband) to issue it." It has nothing to do with the conditional divorce.
Allaah Knows best.