Evidence from Qur'an and Sunnah

 

Having a purificatory bath because of Janabah is obligatory:

Allah says:

]وَإِن كُنتُمْ جُنُبًا فَاطَّهَّرُوا[
(المائدة: 6)

This means: “And if you are in a state of Janabh (i.e. had a sexual discharge), purify yourself (bathe your whole body).” (5, Al-Ma’idah: 6)

Allah says:

]وَلاَ جُنُبًا إِلاَّ عَابِرِي سَبِيلٍ حَتَّىَ تَغْتَسِلُوا[
(النساء: 43)

This means: “Nor when you are in a state of Janabah, (i.e. in a state of sexual impurity and have not yet taken a bath) except when travelling on the road (without enough water, or just passing through a mosque), till you wash your whole body.” (4, An-Nisa’: 43)

The Prophet (peace be upon him) said:

“When anyone sits amidst four parts (of the woman) and the (circumcised) parts touch each other, a bath becomes obligatory.”
(Reported by Al-Bukhari and Muslim)

Having a bath because of menstruation and after giving birth:

Allah says:

]فَاعْتَزِلُواْ النِّسَاء فِي الْمَحِيضِ وَلاَ تَقْرَبُوهُنَّ حَتَّىَ يَطْهُرْنَ[
(البقرة: 222)

This means: “Therefore keep away from women during menses and go not unto them till they are purified (from menses and have taken a bath).” (2, Al-Baqarah: 222)

The Prophet Muhammad (peace be upon him) said to Fatimah Bint Hubaysh:

“Remain away (from prayer) equal (to the length of time) that your menses prevented you. After this (after the period of usual courses), bathe yourself and offer prayer.” (Reported by Muslim)

Newly converted Muslims:

It was narrated that: “the Prophet Muhammad (peace be upon him) ordered Thumamah Al-Hanafi, newly converted to Islam as he was, to have a purificatory bath.” (Reported by Al-Bukhari and Muslim)

Desirable purificatory bath:

Friday:

Allah's Messenger (peace be upon him) said:

“Taking a bath on Friday is essential for every adult person.”
(Reported by Al-Bukhari and Muslim)

Undesirable acts of having a purificatory bath:

To extravagantly use water:

“The Prophet (peace be upon him) used to take a bath with a Sa` (a measure equivalent to four Mudds, three liters approx.) (of water) and perform ablution with a Mudd (A measure of two thirds of a liter of water, approx.).” (Reported by Muslim)

Bathing in open places:

The Prophet (peace be upon him) said:

“Allah is characterized by modesty and concealment. So, when any of you washes, he should conceal himself.”
(Reported by Abu Dawud)

Things that a Junub should not do:

Reciting Qur’an:

`Ali Ibn Abi Talib (may Allah be pleased with him) said:

“The Prophet of Allah (peace be upon him) came out from the privy and taught us the Qur’an and ate meat with us. Nothing prevented him; or the narrator said: Nothing prevented him from (reciting) the Qur’an except sexual defilement.” (Reported by Abu Dawud)

Entering mosques and performing prayers:

Allah says:

]لاَ تَقْرَبُواْ الصَّلاَةَ وَأَنتُمْ سُكَارَى حَتَّىَ تَعْلَمُواْ مَا تَقُولُونَ وَلاَ جُنُبًا إِلاَّ عَابِرِي سَبِيلٍ حَتَّىَ تَغْتَسِلُواْ[ (النساء: 43)

This means: “Approach not As­Salah (the prayer) when you are in a drunken state until you know (the meaning) of what you utter, nor when you are in a state of Janabah (i.e. in a state of sexual impurity and have not yet taken a bath) except when travelling on the road (without enough water, or just passing through a mosque), till you wash your whole body.” (4, An-Nisa’: 43)

Touching the Qur’an:

Allah says:

]لا يَمَسُّهُ إِلا الْمُطَهَّرُون[
(الواقعة: 79)

This means: “Which (that Book with Allah) none can touch but the purified.” (56, Al-Waqi`ah: 79)