All perfect praise be to Allah, The Lord of the Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
Funeral prayer is a collective duty as it is obligatory that is performed on a deceased Muslim and on miscarried fetus-the one aborted spontaneously- if it was more 6 months old, but if the fetus was less, then performing it is an obligation provided that signs of life are recognized by slight movements or gestures; however, funeral prayer isn't to be performed on the Martyr of a battle.
Further, it is due at the very time of washing the deceased by water usually, or the like such as Tayammum if it wasn't obtainable (is allowed whereby one may wipe one's face and arms with dust in a specifically detailed way). In addition, funeral prayer has the same conditions for a valid obligatory prayer as follows: covering private parts, heading toward Qiblah, the purity of body, place of prayer and dress, minor and major impurity aren't taking place. Besides, people who are obliged to perform this prayer most are male blood relatives from father's side.
Moreover, funeral prayer has seven pillars as follows: performing the prayer in standing position for whom is capable for, making one's intention, saying four Takbirat and saying the Tsleem( Final salutations in prayer), since Abu Hurayra (May Allah be pleased with him) said that the Prophet gave the people news of the death of the Negus on the day on which he died, took them out to the place of prayer, drew them up in rows and said “God is most great” four times." [Related by Al-Bukhary]. In general, a person is obliged to make his intention for performing funeral prayer and isn't permitted to mention the name of the deceased, it is performed as follows:
1. The Imam who intends to perform funeral prayer, should stand parallel to the head of a deceased male and to the waist of a deceased female stipulated that he shouldn't stand in an advanced position over he/she.
2. Funeral prayer should be performed in standing position for who is capable, and the one who is incapable is exempted and permitted to perform it while sitting.
3. Surat Al-Fatiha is preferable to be recited after saying the first Takbira, and a person is permitted to recite it after saying any of the four Takbirat; besides, seeking refuge in Allah from the accursed Satan is an act of Sunnah; yet, pronouncing the opening supplication which is usually said at the beginning of the prayers in general isn't an act of Sunnah while performing funeral prayer.
4. Raising the hands of a praying person at every single Takbira is an act of Sunnah.
5. He is obliged to say prayers of the Prophet (PBUH) right after the second Takbira, since saying it after any other won't avail him. In addition, the least acceptable manner of saying prayers of the Prophet is (Oh Allah, send Salah upon Muhammad) and the best manner is (O Allah, send Salah upon Muhammad and upon the family of Muhammad, as You sent Salah upon the family of Ibrahim, and send blessings upon Muhammad and upon the family of Muhammad as You sent blessings upon the family of Ibrahim among the nations. You are indeed Worthy of praise, Full of glory.)''.
6. Save after saying the third Takbira, a praying person is obliged to supplicate sincerely for the sake of a deceased in particular, as supplicating for any other won't avail the former.
7. After saying the fourth Takbira, he is obliged to supplicate for himself and for believers in general through supplicating with " O Allah, do not withhold from us the reward (of faith) and do not lead us astray after his death." In addition of sending prayers over the Prophet (PBUH); however, he is permitted to remain silent after the fourth Takbira
8. He should pronounce Taslim twice; the first while turning his head to his right shoulder and the second while turning his head to left one.
9. Performing funeral prayer at the Mosque is an act of Sunnah in addition to increasing the number of praying persons in order to reach 3 rows and above.
10. Performing it for the absentee funeral prayer is a kind of funeral prayer performed upon a dead Muslim if they die in a place where there are no Muslims to pray for the dead is valid one, since the Prophet did so, as reported by Abu Hurayra (May Allah be pleased with him) where he said that the Prophet gave the people news of the death of the Negus on the day on which he died, took them out to the place of prayer, drew them up in rows and said “God is most great” four times. [Agreed upon]" Thusly, performing it on every absent who passed away far from his home is permissible, stipulated that there was a hardship in attending his funeral or the place/country of burial; further, performing it at the very place where he passed away is permissible as well. Kindly refer to [Mughni Al-Muhtaj].
11. Performing it after the burial of the deceased regardless of its duration is permissible for whom was mature to perform it at the time of deceased's death, as stated :" Whosoever missed funeral prayer is permitted to perform it at the grave of the deceased provided that he was mature and sane at the time deceased's death; otherwise, performing it is invalid." [Omdat As-Salikeen pp.44]. And Allah knows best.