Question Summary:
Learning salah by watching video and about imam Mahdi

Question Detail:

 
1. Is it allowed to learn how to perform prayer by watching a video or reading a book that has pictures of humans in it (i.e. a picture of a man performing a certain part of prayer or taharat)?
2. Is it true that Mahdi is to appear in the beginning of a century? Does that mean he has appeared now because I heard there is a hadeeth saying that the time of this Ummah's existence is no more than 1500 years and our century is therefore the last century?

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh. 
1. Salah is one of the basic and  fundamental pillars of Islam. One should learn how to perform salah with utmost care and concentration.
When salah became fard during the incident of Miraj, Almighty Allah Taala sent Jibraeel (Alaihi Salam) for two consecutive days to teach and demonstrate the procedure and times for salah.
For that, Jibraeel (Alaihi Salam) was the Imam and Rasulullah (Salallahu Alahi Wa Salaam) perform salah behind Jibrail (Alaihi Salam)[1].
Rasulullah (Salallahu Alahi Wa Salaam) in turn practically thought  the Sahaba the procedure of salah. The Sahaba used to take pride in the practically demonstrating the procedure of salah to learn other, after which they would say: “This is how I have seen Rasulullah (Salallahu Alahi Wa Salaam) performed salah”.
This practical demonstration of salah continued in the Tabeen and Tabi Tabeen, and from generation to generation until we have learned the proper and correct procedure of performing salah through the practical demonstration of our teachers.
This procedure of teaching and educating people on salah should continue.
The issue if pictures on videos and electronic images is a subject of academic debate among ulama. It is thus best to avoid using videos and pictures having the head of the person as head constitutes tasweer.
One may use charts having pictures of the different postures of salah with out having the head of a person and which are available[2].
2. The appearance of Imam Mahdi is true. He will appear during the last days of the existence of this world.
The actual life span of this Ummah is not known. The narration of 1500 for this Ummah is incorrect[3].
Allah has concealed the  actual day of judgment and the actual life span of this Ummah.
Rasulullah (Sallahu Aleihi Wa Salaam) said about the day of Judgment:
ما المسؤول عنها بأعلم من السائل[4]
The person questioned does not know more than the questioner.
The closest indication we have of the day of judgment are the minor and major incidents that will take place before the day of judgment[5].
Abu Ali ad-Dagistani                                 
Moscow, Russia
Checked and Approved by,
Mufti Ebrahim Desai