Assalamualaikum w.b.t. When I was performing my umrah recently, someone told me that it is permissible to perform funeral prayer without ablution. Is this true? Hope for an explanation.
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions and all those who follow his footsteps until the Last Day.
We start with the statement of Allah SWT:
وَلِكُلِّ أُمَّةٍ أَجَلٌ ۖ فَإِذَا جَاءَ أَجَلُهُمْ لَا يَسْتَأْخِرُونَ سَاعَةً ۖ وَلَا يَسْتَقْدِمُونَ
“And for every nation is a [specified] term. So, when their time has come, they will not remain behind an hour, nor will they precede [it].” 
The above verse shows that for every generation and time, there is a certain determined period and time for their death. When the decided time came (their death), it will not be delayed even for a moment (second) or hastened. 
Undeniably, there are great rewards for those who performed funeral prayer. This is based on the narration from Abu Hurairah RA, Rasullullah PBUH said:
مَنْ شَهِدَ الْجَنَازَةَ حَتَّى يُصَلَّى عَلَيْهَا فَلَهُ قِيرَاطٌ، وَمَنْ شَهِدَهَا حَتَّى تُدْفَنَ فَلَهُ قِيرَاطَانِ. قِيلَ: وَمَا الْقِيرَاطَانِ؟ قَالَ: مِثْلُ الْجَبَلَيْنِ الْعَظِيمَيْنِ
“Whoever accompanies the funeral of a Muslim, seeking the reward only from Allah, the Almighty, and he stays with it until he offers the funeral prayer and the burial is completed, will return back with two Qirat, each Qirat is equal to the mount of Uhud.” 
Funeral prayer without ablution
Basically, it is conditioned for a funeral prayer to be valid is the same as other prayers to be valid that is the person itself, the clothes he’s wearing and the place he’s going to pray in should be pure. Likewise, one should also be religiously pure (hukmi/spiritually), cover the awrah, face the qibla, and set the intention. The matter that differentiates this and other prayers is only the time for funeral prayer isn’t conditioned to a specific time.  There is a narration from Abdullah bin Umar R.Anhuma, he said:
لَا يُصَلِّي الرَّجُلُ عَلَى الْجَنَازَةِ إِلَّا وَهُوَ طَاهِرٌ
“No one should pray over a dead person unless he is in wudu.” 
Syeikh ‘Abd al-Karim al-Khudhair when discussing the above narration stated that this is the opinion of the majority of the scholars. Furthermore, Ibn ‘Abd al-Bar cited scholars agreed in this matter except for what is narrated by al-Sya’bi whose opinion stated that funeral prayer can be performed without first getting purified. 
Moreover, Imam al-Nawawi also stated that the Muslim ummah has agreed on the prohibition of praying without purification whether it is with water or soil. There is a difference between obligatory, sunnah prayers, tilawah prostration, prostration of gratitude or funeral prayer except for what has been cited by al-Sya’bi and Muhammad bin Jarir al-Tabari who said that the funeral prayer can be performed without purification. This is a batil (incorrect) opinion and scholars have agreed to the opposite – that is funeral prayer cannot be performed without purification.
If a person is in a state of hadas (minor/major impure state) and intentionally prays without any debilitation, he is sinful but isn’t considered a disbeliever according to scholars of madhhab Syafi’I and the majority of scholars – of other madhhabs. Although, there is an opinion cited from Abu Hanifah where he believes that the person is considered a disbeliever, for he is considered a person who mocks the religion. While Shafiite scholars stated that the ruling that a person is considered to have denounced Islam is only for matters that involve iktikad (belief) – or akidah (faith). As for a person praying without performing ablution, his iktikad is still true. All of this is when the person who is in hadas prays when he isn’t experiencing any debility. 
In other words, according to madhhab Syafi’I, funeral prayer is invalid except when a person is in a pure state if he is capable to perform the ablution, and the prayer is invalid except with ablution. If one isn’t capable, then he can perform the tayammum. However, tayammum is invalid if he is capable to use water, even if he fears that he might miss the funeral prayer – that is the funeral prayer has been completed without him. This is the opinion of Imam Malik, Ahmad, Abu Thaur, and Ibn al-Munzir. Whilst Abu Hanifah’s opinion states that it is permissible to perform tayammum when there is water if one fears that he might miss the funeral prayer if he is busied with ablution – due to the water being far away or others. Whereas al-Sya’bi, Muhammad bin Jarir al-Tabari and Syiah believe that funeral prayer can be performed without purification even if one is capable to perform ablution and tayammum because funeral prayer is supplication. 
Ibn Battal explained this opinion of al-Sya’bi saying that he permits funeral prayer without purification from hadas, for it is a supplication and there is no rukuk (bowing) and prostration (sujud) in it. When the jurists have agreed on the opposite opinion – a different opinion from al-Sya’bi’s – and don’t follow this syaz opinion. Moreover, even if this is true, that is even if it is a supplication as claimed by al-Sya’bi, surely, it can be performed without facing the qibla.  Furthermore, it is cited that some previous scholars are of the opinion that funeral prayer is a supplication. Hence, ablution is not a condition for it. Hence, it is said: “Hence, can it be performed without facing the qibla?” Then, they retracted their opinion. 
While the jumhur of scholars are of the opinion that purification from hadas is conditioned when performing the funeral prayer following the statement of Allah SWT:
وَلَا تُصَلِّ عَلَىٰ أَحَدٍ مِّنْهُم مَّاتَ أَبَدًا
“And do not pray [the funeral prayer, O Muhammad], over any of them who has died – ever – or stand at his grave.” 
In the above verse, Allah SWT named the funeral prayer as a prayer. Likewise, in hadiths, it is also named as a prayer. This is as stated by the Prophet PBUH:
مَن صَلَّى علَى جِنازَةٍ فَلَهُ قِيراطٌ
“He who offered prayer over the dead, for him is the reward of one qirat,” 
Thus, when the funeral prayer is included in the category of a type of prayer, then it is bound to the same conditions of prayer that one must be in a pure state (not in the state of hadas) and face the qibla. As for there are a lot of supplication in funeral prayer, this doesn’t exempt it from its category of prayer. 
According to the above arguments and discussions, in our opinion, it is conditioned for a person who wants to perform the funeral prayer to first purify himself and be in a pure state just like it is conditioned for other prayers. Hence, a person must ensure that he is pure from hadas before performing the funeral prayer. Furthermore, Imam al-Nawawi cited that this is the ijmak of the scholars on this matter.
As for the opinion that states that it is permissible to be performed without one being in a pure state, the opinion from al-Sya’bi and Ibn Jarir al-Tabari is syaz – odd and peculiar – and one shouldn’t practise or hold onto this opinion.
May Allah SWT grant us all a clear understanding in religion. Ameen.
 Surah al-A‘raf: 34
 See Mukhtasar fi Tafsir al-Quran al-Kareem, pg. 154.
 Narrated by al-Bukhari (1325); Muslim (945)
 See al-Mausu‘ah al-Fiqhiyyah al-Kuwaitiyyah, 16/18.
 Narrated by Malik in Muwatta’ (787)
 See Syarh al-Muwatta’, 46/8.
 See al-Minhaj Syarh Sahih Muslim, 3/103.
 See al-Majmu‘ Syarh al-Muhazzab, 5/223.
 See Syarh Sahih al-Bukhari, 3/305.
 See Fath al-Bari by Ibn Rejab, 3/92.
 Surah al-Taubah: 84
 Narrated by Muslim (946)
 See al-Majmu‘ Syarh al-Muhazzab, 5/223.