Do You Need Wudu for The Janazah Prayer?
Question

Is the funeral prayer valid without Wudu or Tayammum?
Praise be to Allah.In order for the funeral prayer to be valid, it is essential that one be in a state of purity and free from impurity, which is achieved by doing Wudu or by doing Tayammum if water is not available or one is unable to use it, according to the majority of jurists.
Some scholars narrated that there was consensus on this point, because of the evidence which indicates that purity is essential for prayer, and the funeral prayer is also a form of prayer, so it is essential to be in a state of purity. 
Some of the scholars are of the view that it is permissible to do Tayammum if there is the fear that one may miss the funeral prayer by taking too long to do Wudu. 
As for the view that the funeral prayer may be offered without Wudu or Tayammum, this is attributed to Ash-Sha’bi and Ibn Jarir At-Tabari, but it is an invalid view. 
An-Nawawi (may Allah have mercy on him) said in Al-Majmu` (5/181): 
We have stated that our view is that the funeral prayer is not valid unless one is in a state of purity. What this means is that if one is able to do Wudu, the prayer is not valid without it, and if he is unable to do Wudu he should do Tayammum. Tayammum is not valid when it is possible to use water, even if he fears that he will run out of time and miss the prayer. This is the view of Malik, Abu Thawr and Ibn Al-Mundhir.” 
Abu Haneefah said:
“It is permissible to do Tayammum for it even when water is available, if he fears that he will miss it if he takes too long to do Wudu. Ibn Al-Mundhir narrated that from `Ata’, Salim, Az-Zuhri, `Ikrimah, An-Nakha`i, Sa`d ibn Ibrahim, Yahya Al-Ansari, Rabi`ah, Al-Layth, Ath-Thawri, Al-Awza`i, Is-haq and Ashab Ar-Ra’y, and it is narrated in one report from Ahmad. 
Ash-Sha`bi, Muhammad ibn Jarir At-Tabari and the Shi`ah said that it is permissible to offer the funeral prayer without being in a state of purity, even if one is able to do Wudu or Tayammum, because it is a Du`a’. The author of Al-Hawi and others said: What Ash-Sha`bi said is a view that is contrary to consensus, so no attention should be paid to it. 
Our evidence that purification is essential is the words of Allah (interpretation of the meaning): “And never (O Muhammad) pray (funeral prayer) [wa la tusalli] for any of them (hypocrites) who dies” [At-Tawbah 9:84]. So He called it salah (prayer). 
It is narrated by Al-Bukhari and Muslim that the Prophet (peace and blessings of Allah be upon him) said: “Offer the (funeral) prayer for your companion (sallu ‘ala sahibikum).” And he (peace and blessings of Allah be upon him) said: “Whoever offers the funeral prayer (man salla ‘ala Janazah) …”, and in other Hadiths he called it prayer. Allah says (interpretation of the meaning): “When you intend to offer As-Salah (the prayer) [idha qumtum ila As-Salah], wash your faces and your hands (forearms)” [Al-Ma’idah 5:6]. In As-Saheeh, the Prophet (peace and blessings of Allah be upon him) said: “Allah does not accept any prayer (Salah) without purification.” The fact that much of its purpose is supplication (for the deceased) does not cancel out the fact that it is a prayer (salah).” 
And Allah knows best.