This report is of the highest degree of soundness. Imam Maalik narrated it in al-Muwatta’ (535) from Naafi’ from ‘Ibn ‘Umar, and this is what some of the scholars called al-silsilah al-dhahabiyyah (the golden chain), which is the soundest, or one of the soundest, of isnaads. 

The wording is: It was narrated from Naafi’ that ‘Abd-Allaah ibn ‘Umar did not recite in the funeral prayer. 

The meaning of the phrase “did not recite” is that he did not recite the Opening of the Book (al-Faatihah) or anything else. This is one of the well-known topics of dispute among the scholars. Some of them are of the view that it is a pillar or essential part of the funeral prayer, and others are of the view that it is not a pillar or even mustahabb. Others adopt a middle view and say that it is mustahabb but not obligatory. This is the view favoured by Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) who said: 

The scholars differed concerning recitation of Qur’aan in the funeral prayer. There are three views. It was said that it is not mustahabb under any circumstances, as is the view of Abu Haneefah and Maalik. And it was that it is obligatory to recite al-Faatihah, as is the view of some of the companions of al-Shaafa’i and Ahmad. And it was said that reciting al-Faatihah in the funeral prayer is Sunnah, but not reciting it and saying du’aa’ without reciting is permissible. This is the correct view. End quote. 

Al-Fataawa al-Kubra’, 2/121 

It seems – and true knowledge belongs to Allaah – that reciting al-Faatihah is a pillar or essential part of the funeral prayer. This comes under the general meaning of the words of the Prophet (peace and blessings of Allaah be upon him): “There is no prayer for the one who does not recite the Opening of the Book.” Narrated by al-Bukhaari, 714; Muslim, 595. Perhaps because Ibn ‘Umar held this view, Ibn ‘Abbaas used to recite it out loud sometimes, although the Sunnah is to recite it quietly, in order to demonstrate that it should be recited in the funeral prayer. He was asked about that and he said: “So that you will know that it is Sunnah.” Narrated by al-Bukhaari, 1249. 

His saying that it is Sunnah does not mean that it is mustahabb, rather what he means is that it was the way of the Prophet (peace and blessings of Allaah be upon him), i.e., the Prophet (peace and blessings of Allaah be upon him) used to recite it. 

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said: 

Al-Faatihah is a pillar or essential part of the funeral prayer, because the Prophet (peace and blessings of Allaah be upon him) said: “There is no prayer for the one who does not recite the Opening of the Book,” and the funeral prayer is a prayer, because Allaah says (interpretation of the meaning): “And never (O Muhammad) pray (funeral prayer) for any of them (hypocrites) who dies” [al-Tawbah 9:84].  So Allaah calls it a prayer (salaah). And Ibn ‘Abbaas (may Allaah be pleased with him) recited al-Faatihah in the funeral prayer, and said: “So that you will know that it is Sunnah.” 

Al-Sharh al-Mumti’, 5/401 

Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him) was asked: 

What is the ruling on reciting al-Faatihah in the funeral prayer?  

He replied: 

It is obligatory, as the Prophet (peace and blessings of Allaah be upon him) said: “Pray as you have seen me praying.” And he (peace and blessings of Allaah be upon him) said:  “There is no prayer for the one who does not recite the Opening of the Book.” Saheeh – agreed upon. 

Majmoo’ Fataawa al-Shaykh Ibn Baaz, 13/143 

And Allaah knows best.