As mentioned earlier, performing the wudu is always a recommendable deed, but it becomes obligatory (wajib) in certain circumstances. There are five circumstances under which wudu becomes obligatory; and whenever a Muslim finds himself in any one these circumstances, he must do wudu.
The five circumstances are as follows:-
1. For obligatory prayers, e.g., the five daily prayers.
Wudu is not wajib for sunnat (recommended) prayers; but as the prayers whether obligatory or recommended are invalid without wudu, so we have to pray the sunnat prayers also with wudu. In other words, if you do not do wudu for the sunnat prayer you will not have sinned-although your prayer will be incorrect. Imam Muhammad al-Baqir (a.s.) said, “There can be no prayer except with ritual ablution (i. e. wudu).” 434
Salatu ‘l-mayyit (the ritual prayer said for the dead person before the burial) is an exception to this rule; this obligatory prayer can be performed even if one is in a state of ritual impurity.
2. For the wajib circumambulation (tawaf) of the Ka`bah in hajj. ‘Ali bin Ja`far asked his father (the sixth Imam) about a person who was doing the tawaf and then remembered that he had not done wudu. Imam Ja’far as-Sadiq (a.s.) said, “He should stop the tawaf and not count (whatever he had done as valid). 535
3. For touching the writings of the Qur’ an. The Qur’an is not just a book, it is the revelation of God, it is the word of God, and therefore it is sacred. Its sacredness demands that before you touch the writing of the Qur’an, you must ritually purify yourself. Allah says,
“None shall touch it except the purified ones.” (56:79)
On basis of the extrinsic meaning of this verse and the ahadith, the mujtahids have reached the opinion that it is forbidden to
touch the writings of the Qur’ an without being in the state of wudu.
However, this law of the shari`ah should not become an excuse for not reading the Qur’an. There is no harm in reading the Qur’an without doing wudu provided one does not touch the writing of the holy book, i.e., just hold the cover or the border of the page. Once Imam Ja’far as-Sadiq (a.s.) told his son Isma’il to read the Qur’an . Isma’il said, “I am not in the state of wudu.” The Imam said, “Do not touch the writing, just hold the paper and then read the book.” 636
Likewise, there is no harm in touching the translations of the Qur’an, because the translations do not qualify as the word of God. Neither is it wajib to prevent the children from touching the writings of the Qur’an unless such an act is considered a disrespect to the Sacred Book-and this differs according to the culture and the society’ in which the Muslims live.
4. For touching the names and the attributes of Allah.
It is forbidden to touch the names and the attributes of Allah, in any script, without being in the state of ritual purity (wudu).
By looking at the sacredness which the Prophets, the Imams of the Ahlu ‘l-bayt
and also Fatimah (the daughter of the Prophet) have acquired due to their being chosen by Allah, our mujtahids have recommended that the names of these holy persons also should not be touched without wudu.
5. For making promise, oath and vow to stay in the state of ritual purity (i.e., in wudu) for a certain period of time. If a person makes such a promise or vow, then he must fulfill it when his conditions have materialized. For example, someone says, “If I pass my exams, I will stay with wudu for a whole day.” So if this person passes his exams, then he must stay with wudu for one full day.