Purpose of funeral prayer is to supplicate for deceased
30-6-2017 | IslamWeb
Question:
Assalaamu alaykum. My first question is that I would like to know the history behind this month Rabee‘ Al-Awwal. The second question is: why do we pray for the deceased person, and is it really necessary to know the person's gender before the funeral prayer? Wassalaam.
Answer:
All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
Allah, The Exalted, prescribed the funeral prayer for the deceased. An-Nawawi 
wrote, "Scholars unanimously agreed that the funeral prayer is a collective obligation."
One of the rationales behind prescribing the funeral prayer is to supplicate Allah in favor of the deceased and seek forgiveness and pardon for them. Ibn Al-Qayyim wrote, "The ultimate purpose of the funeral prayer is to supplicate Allah in favor of the deceased. This is why it was reported that the Prophet, sallallahu ‘alayhi wa sallam, used to perform the funeral prayers for the dead Muslims in a far greater number of reports and ahaadeeth compared to those narrated about reciting the Faatihah and invoking blessings and prayers upon him..."
Knowing the deceased by name or knowing whether the deceased is a man or a woman is not required; it is sufficient for the praying person to hold the intention of supplicating for the deceased present at that time. An-Nahr Al-Faa'iq reads, "The praying person should hold the intention of performing the funeral prayer and of supplicating Allah in favor of the deceased because this is the obligation. It is better not to specify the deceased by name when the person is not sure who it is."
Ar-Raafi‘i said, "It is not required to specify the name of the deceased (in the supplication of the funeral prayer) or to know them in person."
As for your first question, we do not understand what you exactly mean by it, and it is not relevant to our website, as the website is concerned with giving fatwa.
Allah knows best.