On Divorce Before Puberty, and Swearing by Divorce About a Matter One Believes

Answer—and Allah grants success: If a divorce issued from him and he became unsure whether it was before puberty or after, the default is non-puberty. Thus, the child’s divorce does not occur. This accords with the madhhab’s principles. Its proof is His saying, Exalted is He: “And do not pursue that of which you have no knowledge” [Al-Isrāʾ:36]—childhood is known, puberty is unknown; and His saying: “Indeed, assumption avails not against the truth at all” [Yūnus 10:36].
Yes—this is what judgment and fatwā require. If a Muslim takes extra caution, that is better and safer for him—per his saying (May Allah bless him and his family and grant them peace): “Leave what makes you doubt for what does not make you doubt.”
As for swearing by divorce regarding a matter the swearer believes—he believes it to be as he swore, but it turns out otherwise—the closer view is that divorce does not occur, for several reasons:
1. It is believed that this man is telling the truth. It has been said that truthfulness is conformity to belief, without regard to correspondence to external reality.
2. Such belief is legally recognized and rulings are built upon it. For example, a mujtahid is obligated by what he believes to be preponderant and may not contravene his belief—whence it is said, “Every mujtahid is correct.” Likewise, one who believes the liquid in a flask to be wine may not drink it—even if it is water. If he drinks it while believing it to be wine, he is sinful. This indicates that rulings attach to what a person believes, not to external reality.
3. It has been said: The criterion for the validity or invalidity of rulings is the initial state. One who stood in ʿArafah thinking he was in the ḥaram, then discovered his mistake—his standing is valid, by regard to the initial state. This is the madhhab.1
4. The default is the continuance of the marriage.
5. His saying—Exalted is He: “Allah does not impose blame upon you for what is unintentional in your oaths, but He imposes blame upon you for what your hearts have earned” [Al-Baqarah:225]. This oath is laghw.
6. His saying—Exalted is He: “There is no blame upon you for that in which you have erred but [only] for what your hearts intended” [Al-Aḥzāb:5].2. Such belief is legally recognized and rulings are built upon it. For example, a mujtahid is obligated by what he believes to be preponderant and may not contravene his belief—whence it is said, “Every mujtahid is correct.” Likewise, one who believes the liquid in a flask to be wine may not drink it—even if it is water. If he drinks it while believing it to be wine, he is sinful. This indicates that rulings attach to what a person believes, not to external reality.
3. It has been said: The criterion for the validity or invalidity of rulings is the initial state. One who stood in ʿArafah thinking he was in the ḥaram, then discovered his mistake—his standing is valid, by regard to the initial state. This is the madhhab.1
4. The default is the continuance of the marriage.
5. His saying—Exalted is He: “Allah does not impose blame upon you for what is unintentional in your oaths, but He imposes blame upon you for what your hearts have earned” [Al-Baqarah:225]. This oath is laghw.
6. His saying—Exalted is He: “There is no blame upon you for that in which you have erred but [only] for what your hearts intended” [Al-Aḥzāb:5].
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1