Regarding it, there are two narrations from Ahmad, which were mentioned by Ibn Abi Musa. One of them: an expiation is incumbent upon him, because he swore by manumission in a matter where it does not occur upon breaking the oath, so an expiation became mandatory for him, just as if he said: 'It is incumbent upon me to Allah to manumit so-and-so.' The second: there is no expiation upon him, because he swore to dispose of another person's property, so nothing became incumbent upon him, just as if he said: 'The property of so-and-so is charity if I enter the house.' And because it is an attachment of manumission to a quality, so no expiation is required by it, like other cases of attachment. As for when he says: 'It is incumbent upon me to Allah to manumit a slave,' it is a vow, so it necessitates expiation because a vow is like an oath, whereas that is not the case here; for he only attached the manumission to a quality, so the existence of the quality has the effect of making the attached thing like the immediate thing, and if the manumission were immediate, nothing would be incumbent upon him, so it is likewise here.
Section: If he says: 'If I do such and such, then the property of so-and-so is charity,' or 'So-and-so owes a pilgrimage,' or 'The property of so-and-so is unlawful to him,' or 'He is free from Islam,' and things similar to this, it is not an oath, and no expiation is required for it. We do not know of any disagreement among the people of knowledge regarding it, because the Sharia did not stipulate an expiation for it, nor is it in the meaning of that for which the Sharia has stipulated it.
1796- Issue: He said: '(And whoever swears an oath is given a choice regarding the expiation before breaking the oath and after it, and it is the same whether the expiation is fasting or something else, except in the cases of zihar and haram, for he must perform the expiation before breaking the oath.)'
Zihar and haram are one and the same thing, and he only coupled one with the other due to the difference in the terms used. There is no disagreement among the scholars, as far as we know, regarding the necessity of performing the expiation prior to sexual intercourse. The basis for this is the statement of Allah Almighty: '...then a neck must be freed before they touch one another.' As for the expiation of other oaths, it is permissible both before the breaking of the oath and after it, whether it is fasting or otherwise, according to the opinion of the majority of the people of knowledge. Malik also held this view. Among those from whom it was reported that performing the expiation in advance is permissible are 'Umar ibn al-Khattab, his son, Ibn 'Abbas, Salman al-Farisi, and Maslamah ibn Mukhallad, may Allah be pleased with them. This was also the view of al-Hasan, Ibn Sirin, Rabi'ah, al-Awza'i, al-Thawri, Ibn al-Mubarak, Ishaq, Abu 'Ubayd, Abu Khaythamah, and Sulayman ibn Dawud. The proponents of Ra'y (scholarly opinion) said: The expiation is not valid before the breaking of the oath, because it is an expiation...
(1) Surah al-Mujadilah: 3.