Praise be to Allah.
If the wife stipulates that her husband should not take a second wife, this is a valid condition that must be fulfilled, and if he does take a second wife, she has the right to annul the marriage, because of the report narrated by al-Bukhaari (2721) and Muslim (1418) according to which the Messenger of Allah (blessings and peace of Allah be upon him) said: “The conditions that are most deserving to be fulfilled are those by means of which intimacy becomes permissible for you.”
This has been discussed previously in fatwa no. 143120.
But if the wife stipulates that her husband should not offer naafil prayers, this is an invalid condition and he is not obliged to fulfil it. It is invalid because it is contrary to the Book of Allah, may He be exalted, and in opposition to it, and whatever is like that is invalid, because the Prophet (blessings and peace of Allah be upon him) said: “What is the matter with people who stipulate conditions that are not in accordance with the Book of Allah? Whoever stipulates a condition that is not in accordance with the Book of Allah, it is invalid, even if he stipulates a hundred conditions. The Book of Allah is more valid and the conditions stipulated by Allah are more deserving of being adhered to.”
It is contrary to the Book of Allah, may He be exalted, because Allah, may He be glorified, has enjoined the doing of good, and offering a lot of naafil prayers. Allah, may He be exalted, says (interpretation of the meaning):
“O you who have believed! Bow down, and prostrate yourselves, and worship your Lord and do good that you may be successful”
Allah, may He be exalted, praised the pious for offering a lot of prayers at night (qiyaam al-layl) and sleeping only a little, as He, may He be exalted, says (interpretation of the meaning):
“Verily, the Muttaqûn (pious) will be in the midst of Gardens and Springs (in the Paradise),
Taking joy in the things which their Lord has given them. Verily, they were before this Muhsinûn (good-doers)
They used to sleep but little by night [invoking their Lord (Allâh) and praying, with fear and hope].
And in the hours before dawn, they were (found) asking (Allâh) for forgiveness”
“And the (faithful) slaves of the Most Gracious (Allâh) are those who walk on the earth in humility and sedateness, and when the foolish address them (with bad words) they reply back with mild words of gentleness.
And those who spend the night in worship of their Lord, prostrate and standing”
And Allah praised a group among the People of the Book, as He said (interpretation of the meaning):
“Not all of them are alike; a party of the people of the Scripture stand for the right, they recite the Verses of Allâh during the hours of the night, prostrating themselves in prayer”
[Aal ‘Imraan 3:113].
With regard to the differentiation between the two, it is that the woman has a valid reason to stipulate that her husband not take a second wife, because women are jealous by nature, especially towards co-wives. This is something inherent in women, and no one is free of it, even the wives of the Prophet (blessings and peace of Allah be upon him, and may Allah be pleased with them). It was narrated that ‘Aa’ishah (may Allah be pleased with her) said: I never felt jealous of any wife of the Prophet (blessings and peace of Allah be upon him) as I felt jealous of Khadeejah, although she had died before he married me, because of what I used to hear of him mentioning her. Narrated by al-Bukhaari (3815).
Al-Bukhaari (5225) narrated that Anas said: The Prophet (blessings and peace of Allah be upon him) was with one of his wives, and one of the Mothers of the Believers sent a platter on which there was some food. The one in whose house the Prophet (blessings and peace of Allah be upon him) was struck the servant’s hand, and the platter fell and broke. The Prophet (blessings and peace of Allah be upon him) picked up the broken pieces of the platter, then he collected in the food that had been on the platter, saying: “Your mother was jealous.” Then he kept the servant waiting until he brought a platter from the one in whose house he was, and he gave the intact platter to the one whose platter had been broken, and kept the broken platter in the house of the one who had broken it.
Moreover, a woman is also affected if she has a co-wife, apart from the matter of jealousy, because instead of having her husband with her every night, there will be a need to divide his time between her and her co-wife or co-wives, so her share of him will be less, and she will have to share with others her maintenance and the maintenance of her household. All of that will obviously lead to a reduction in her share of her husband and his wealth. But with regard to acts of worship, such as naafil prayers and others, there is no valid reason to stipulate that her husband refrain from doing them, in addition to the fact that such a condition is contrary to the objectives of the Lawgiver.
This is the difference between the two conditions: the first one has an obvious benefit, so it is permissible for her to stipulate it, whereas in the case of the second one, there is no benefit for her in it, so it is not permissible for her to stipulate it.
With regard to the opinions of Shaykh Ibn Baaz and Shaykh al-Albaani, we have not come across any comment from either of them concerning this issue.
And Allah knows best.