Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
It is preferred to have wudu for the following actions: while mentioning the name of Allah, going to sleep, to remove a sexual impurity, before performing ghusl, before eating food touched by fire, and renewing the wudu for every prayer.
In his famous work, Fiqh As-Sunnah, Sheikh Sayyid Sabiq, elaborates on the subject as follows:
It is preferred to have wudu for the following actions:
- While mentioning the name of Allah
Al-Muhajir ibn Qunfuzh related that he greeted the Prophet (peace be upon him) but that the latter did not return his salutation until he had made wudu: โThere is nothing that prevented me from responding to you except that I do not like to mention the name of Allah unless I am in a state of purity.โ
Said Qatadah, โBecause of this, al-Hassan hated to recite the Quran or mention Allahโs name unless he had performed wudu. (Ahmad, Abu Dawud, an-Nasaโi and Ibn Majah)
Raeported Abu Juhaim ibn al-Harith, โThe Prophet (peace be upon him) met a person at the well of Jaml, who greeted him, but he did not return his greeting until he had wiped his face and hands.โ (Ahmad, al-Bukhari, Muslim, Abu Dawud and an-Nasaโi) This action was one of preference, not of obligation.
Mentioning the name of Allah is permissible for the one who is in a state of purity, one who has a minor impurity, a person in post-sex impurity, or one who is standing, sitting, and so on.
Aishah said, โThe Messenger of Allah used to remember Allah at all times.โ (Related by โthe five,โ except for an-Nasaโi)
Al-Bukhari recorded it in mu`alliq form.) `Ali reported, โThe Messenger of Allah would come from relieving himself, recite to us and eat meat with us. Nothing would stop him from the Qurโan except post-sex impurity.โ (Related by โthe five.โ At-Tirmidhi and Ibn as-Sakin categorized it as sahih)
- Going to sleep
Al-Barraโ ibn `Aazib reported that the Messenger of Allah (peace be upon him) said, โWhen you go to your bed, perform wudu, lie on your right side and then say, โO Allah, I submit my soul to You, and I turn my face to You. I entrust my affairs to You. I retreat unto You for protection with hope and fear in You. There is no resort and no savior but You. I affirm my faith in Your books which You revealed and in Your prophets you sent.โ If you die during that night, you will be along the natural path. Make it your final statement (of the night). He reported that he repeated this supplication to the Prophet (peace be upon him) and he said, โโฆand Your messengers.โ The Prophet interjected, โNo,โฆ โand the prophets You sent.โ (Ahmad, al-Bukhari, and at-Tirmidhi)
This also applies to one who is in post-sex impurity . Ibn `Umar asked the Prophet, โO Messenger of Allah, can one of us sleep while he is in post-sex impurity?โ The Prophet answered, โYes, if he makes wudu.โ Aishah reported, โWhen the Prophet (peace be upon him) wanted to sleep in a state of post-sex impurity, he would wash his private parts and perform wudu.โ (Related by โthe groupโ)
- To remove a sexual impurity
If a person in a state of post-sex impurity wants to eat, drink or have intercourse again, he should perform wudu.
Aishah said, โWhen the Prophet (peace be upon him) was in a state of impurity because of intercourse and wanted to eat or sleep, he would perform wudu.โ โAmmar ibn Yasar reported that the Prophet permitted a person in post-sex impurity to eat, drink or sleep if he performed wudu first. (Related by Ahmad and at-Tirmidhi, who classified it as sahih.)
Abu Sa`eed reported that the Prophet (peace be upon him) said, โIf one has intercourse with his wife and wants to repeat the act, he should perform wudu.โ (Related by โthe group,โ except for al-Bukhari. Ibn Khuzaimah, Ibn Hibban and al-Hakim recorded it with the addition, โIt makes the return more vivacious.โ)
- Before performing ghusl
It is preferred to perform wudu before ghusl regardless of whether that particular ghusl was an obligatory or a preferred act. Aishah said, โWhen the Messenger of Allah (peace be upon him) performed post-sex ghusl, he would begin by washing his hands and then pour water from his right hand to his left and wash his private parts. He would then perform wudu..โ (Related by โthe group.โ)
- Before eating food touched by fire
Ibrahim ibn Abdullah ibn Qarizh said, โI passed by Abu Hurairah while he was performing wudu and he said, โDo you know why I am making wudu? It is because I ate some yoghurt dried over a fire, for I heard the Messenger of Allah say, โPerform wudu before eating food touched by fire.โ (Related by Ahmad, Muslim and โthe four.โ)
Aishah related that the Prophet (peace be upon him) said, โPerform wudu from whatever touches fire.โ (Related by Ahmad, Muslim, an-Nasaโi and Ibn Majah) This order is one of preference as the following hadith makes clear: โAmr ibn Umayyah azh-Zhamari said, โI saw the Messenger of Allah (peace be upon him) cutting a piece of a sheepโs shoulder and eating it. He was then called to prayer. He put the knife down, prayed, and did not perform another wudu.โ (Al-Bukhari and Muslim)
- Renewing the wudu for every prayer
Buraidah said, โThe Prophet (peace be upon him) made wudu for every prayer. On the day of the conquest of Makkah, he made wudu, wiped over his socks and prayed a number of times with just one wudu. โUmar said to him, โO Messenger of Allah, you did something that you have not done (before).โ He answered, โI did it on purpose, โUmar.โโ (Related by Ahmad, Muslim and others)
Anas ibn Malik said, โThe Prophet (peace be upon him) used to make wudu for every prayer.โ He was asked, โAnd what did you people use to do?โ Malik said, โWe prayed the prayers with one wudu unless we nullified it.โ (Related by Ahmad and al-Bukhari)
Abu Hurairah reported that the Prophet said, โWere it not to be a hardship on my people, I would order them to make wudu for every prayer.โ (Related by Ahmad with a hasan chain)
Ibn โUmar reported that the Prophet (peace be upon him) said, โWhoever makes wudu while he is already in a state of purity will have ten good deeds written for him.โ (Abu Dawud, at-Tirmidhi, and Ibn Majah)
Almighty Allah knows best.