Allah said,

﴿إِذَا قُمْتُمْ إِلَى الصَّلوةِ﴾

(When you stand for (intend to offer) the Salah,) Allah commanded performing Wudu' for the prayer. This is a command of obligation in the case of impurity, and in the case of purity, it is merely a recommendation. It was said that in the beginning of Islam, Muslims had to perform Wudu' for every prayer, but later on, this ruling was abrogated. Imam Ahmad bin Hanbal recorded that Sulayman bin Buraydah said that his father said, "The Prophet used to perform Wudu' before every prayer. On the Day of Victory, he performed Wudu' and wiped on his Khuffs and prayed the five prayers with one Wudu'. `Umar said to him, `O Messenger of Allah! You did something new that you never did before.' The Prophet said,

«إني عمدا فعلته يا عمر»

(`I did that intentionally O `Umar!)''' Muslim and the collectors of the Sunan also recorded this Hadith. At-Tirmidhi said,"Hasan Sahih.'' Ibn Jarir recorded that Al-Fadl bin Al-Mubashshir said, "I saw Jabir bin `Abdullah perform several prayers with only one Wudu'. When he would answer the call of nature, he performed Wudu' and wiped the top of his Khuffs with his wet hand. I said, `O Abu `Abdullah! Do you do this according to your own opinion' He said, `Rather, I saw the Prophet do the same thing. So, I do what I saw the Messenger of Allah doing.''' Ibn Majah also recorded this Hadith. Ahmad recorded that `Ubaydullah bin `Abdullah bin `Umar was asked; "Did you see `Abdullah bin `Umar perform Wudu' for every prayer, whether he was in a state of purity or not,'' So he replied, "Asma' bint Zayd bin Al-Khattab told him that `Abdullah bin Hanzalah bin Abi `Amir Al-Ghasil told her that the Messenger of Allah was earlier commanded to perform Wudu' for every prayer, whether he needed it or not. When that became hard on him, he was commanded to use Siwak for every prayer, and to perform Wudu' when Hadath (impurity) occurs. `Abdullah (Ibn `Umar) thought that he was able to do that (perform Wudu' for every prayer) and he kept doing that until he died.'' Abu Dawud also collected this narration. This practice by Ibn `Umar demonstrates that it is encouraged, not obligatory, to perform Wudu' for every prayer, and this is also the opinion of the majority of scholars. Abu Dawud recorded that `Abdullah bin `Abbas said that when the Messenger of Allah once left the area where he answered the call of nature, he was brought something to eat. They said, "Should we bring you your water for Wudu'' He said,

«إنَّمَا أُمِرْتُ بِالْوُضُوءِ إِذَا قُمْتُ إِلَى الصَّلَاة»

(I was commanded to perform Wudu' when I stand up for prayer.) At-Tirmidhi and An-Nasa'i also recorded this Hadith and At-Tirmidhi said, "This Hadith is Hasan.'' Muslim recorded that Ibn `Abbas said, "We were with the Prophet when he went to answer the call of nature and when he came back, he was brought some food. He was asked, `O Messenger of Allah! Do you want to perform Wudu'' He said,

«لِمَ؟ أَأُصَلِي فَأَتَوَضَّأ»

(`Why Am I about to pray so that I have to make Wudu'.)