al-tabadhdhul (التَّبَذُّل) when it means to give up beautification can at times be wājib (obligatory) and at times it can be masnūn. At times it can be makrūh (disliked) and at times it can be mubāh (permissible). And the 'asl is that it is mubāh.

It is wājib in cases such as when the husband of a woman dies or she has been given a separating divorce.

The evidence for it being wājib for the woman whose husband has died is the following:

And those who are taken in death among you and leave wives behind - they, [the wives, shall] wait four months and ten [days]. And when they have fulfilled their term, then there is no blame upon you for what they do with themselves in an acceptable manner. And Allah is [fully] Acquainted with what you do.

Qur'ān 2:234

It was narrated from Safiyyah bint Abi 'Ubaid that she heard Hafsah bint 'Umar, the wife of the Prophet, (narrate) that the Prophet said:

"It is not permissible for a woman who believes in Allah and the Last Day to mourn for anyone who dies for more than three days except for a husband; she should mourn for him for four months and ten (days)."

Sunan al-Nasaa'i Hadīth No. 3503

al-tabadhdhul also refers to wearing clothes which one wears when one is preoccupied or when one is doing chores at home.

In this meaning al-tabadhdhul is masnūn (a Sunnah) when one prays to Allāh for rain, and the evidence is the following Hadīth:

It was narrated from Hisham bin Ishaq bin Abdullah bin Kinanah that:

His father said: "One of the governors sent me to Ibn Abbas to ask him about the prayer for rain. He said: 'What kept him from asking me? The Messenger of Allah (sallallaahu alayhi wa sallam) went out humbly, (dressed) in a state of humility, submissiveness and beseeching, and he prayed two rak'ahs as in the Eid prayer, but he did not deliver a Khutbah like this Khutbah of yours.'"

Sunan al-Nasaa'i Hadīth No. 1521

al-tabadhdhul is makrūh when it comes to the Friday and Eid prayers. To beautify oneself for these prayers is a Sunnah by consensus of the scholars. One does ghusl and wears the best clothes one has. One also puts on fragrance.

The ahadīth in regards to this are many.

Abu Sa'id al-Khudri and Abu Hurairah reported the Messenger of Allah (sallallaahu alayhi wa sallam) as saying:

If anyone takes a bath on Friday, puts on his best clothes, applies a touch of perfume if has any, then goes to congregational prayer (in the mosque), and takes care not to step over people, then prayer what Allah has prescribes for him, then keeps silent from the time his Imam comes out until he finishes his prayer, it will atone for his sins during the previous week.

Abu Hurairah said: (It will atone for his sins) for three days more. he further said: One is rewarded ten times for doing a good work.

Abu Dawud said: The version narrated by Muhammad bin Salamah is perfect, and Hammad did not make a mention of the statement of Abu Hurairah.

Sunan Abī Dāwud Hadīth No. 343

It was narrated from ‘Abdullah bin Salam that he heard the Messenger of Allah (sallallaahu alayhi wa sallam) saying on the pulpit one Friday:

“There is nothing wrong with anyone of you buying two garments for Friday (prayer), other than his daily work clothes.” (Another chain) from Yusuf bin Abdullah bin Salam that his father said: "The Prophet delivered a sermon to us" and he mentioned that.

Sunan Ibn Mājah Hadīth No. 1148

The above is in regards to men.

As for women, they are to do ghusl with water but they are not to put on perfume or where clothes which make them stand out if they choose to attend Friday and Eid prayers. The evidence is the following Hadīth

Narrated AbuHurayrah:

Do not prevent the female servants of Allah from visiting the mosques of Allah, but they may go out (to the mosque) having not perfumed themselves.

Sunan Abi Dāwud Hadīth No. 565

These ahadīth show that al-tabadhdhul is makrūh for men when they attend the Friday and Eid prayers but mustahabb for women when they attend Eid and Friday prayers.

al-tabadhdhul is makrūh (disliked) for the wife for the husband and for the husband for the wife because it is mustahabb that both beautify themselves for the other based on the following Verses of the Qur'ān

And live with them in kindness.

Qur'ān 4 Portion of Verse 19

And due to the wives is similar to what is expected of them, according to what is reasonable

Qur'ān 2 Portion of Verse 228

Just like the husband loves that his wife beautify herself for him, likewise she loves it that he beautify himself for her.

Abu Zaid said: Be fearful of Allāh in regards to them just like they are fearful in regards to you.

Ibn Abbās has been reported to have said: I love to beautify myself for my wife just like I love that she beautify herself for me because of the following Verse of the Qur'ān

And due to the wives is similar to what is expected of them, according to what is reasonable

Qur'ān 2 Portion of Verse 228

Muhammad bin al-Hasan would wear clean nice clothes and say: I have wives and female slaves and so I adorn myself lest they look at someone other than me.

Abu Yusuf said: It pleases me that my wife adorn herself for me just like it pleases her that I adorn myself for her.

The Kuwati Encyclopedia of Fiqh