Supplication in the funeral prayer

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that whenever a bier was brought and placed before him, he would turn toward the people and say: "You have all come here as intercessors, so intercede for this deceased, for I heard the Messenger of Allah (peace and blessings be upon him) say: 'A group of one hundred men is an ummah (a whole community), and whenever an ummah (a large group) gathers and sincerely supplicates for one of their deceased, Allah Almighty, through the blessing of their supplication, forgives that deceased's sins and forgives them all.'"
This hadith is munqati' (has a broken chain), because Ata al-Khurasani did not live in the time of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him).
Ibn Abi Umar also narrated something similar through the chain of al-Muqri, Sa'id bin Abi Ayyub and Uthman bin Ata.

It is narrated from al-Muttalib (may Allah have mercy on him) that Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) stood up to lead a funeral prayer. He said the takbir, then recited Surah al-Fatihah aloud; after that he sent blessings upon the Prophet (peace and blessings be upon him), then said the takbir and supplicated sincerely for the deceased, then said another takbir and supplicated for the believing men and women. After the prayer he turned to the people and said: "O people, by Allah, I raised my voice in the recitation only so that you would know that it is the Sunnah."
I (Ibn Hajar) say: Reciting Surah al-Fatihah in the funeral prayer and calling it the Sunnah is also established in Sahih al-Bukhari.

It is narrated from Sayyidah Aishah (may Allah be pleased with her) that she heard the Messenger of Allah (peace and blessings be upon him) making this supplication in the funeral prayer: "'Allahumma-ghfir lahu, wa salli 'alayhi, wa awridhu hawda rasulik' (O Allah, forgive him, send down Your mercy upon him, and bring him to the Pond of al-Kawthar of Your Messenger (peace and blessings be upon him))."
The hadith scholars differ about the trustworthiness of Asim bin Hilal, a narrator in the chain of this hadith.

It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that he said: "In the funeral prayer we used to recite (this supplication): 'Allahumma anta rabbuna wa rabbuhu, khalaqtahu wa razaqtahu, ahyaytahu wa kafaytahu, ighfir lana wa lahu, wa la tahrimna ajrahu, wa la tudillana ba'dah' (O Allah, You are our Lord and You are also his (the deceased's) Lord; You created him and blessed him with provision; You gave him life and You sufficed him in the needs of his life; so pardon and forgive us and him, do not deprive us of his reward, and do not let us fall into misguidance after him)."

This same narration is also reported from Sayyiduna Abu Hurayrah (may Allah be pleased with him) through another chain.

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that whenever the Prophet (peace and blessings be upon him) offered a funeral prayer, he would make this supplication: 'Allahumma 'abduka wa ibnu 'abdika, kana yashhadu an la ilaha illa ant' (O Allah, this was Your servant and the son of Your servant; he used to testify that there is no god worthy of worship except You). Then the narrator mentioned the complete hadith.
Its chain is sahih (authentic). Imam Ibn Hibban narrated it by way of Imam Abu Ya'la, but it has a hidden defect ('illah). Imam al-Bayhaqi narrated it through another chain from Sa'id al-Maqburi, Sayyiduna Abu Hurayrah and Sayyiduna Ubadah bin al-Samit (may Allah be pleased with them) as mawquf (a Companion's own statement).