How was the prayer imposed?.
The Night Journey was one of the miracles with which Allah, Almighty, supported His Messenger Muhammad (PBUH), and it took place in the tenth year of His mission. The Prophet (PBUH) was taken on a night journey from the Sacred Mosque (Ka'bah) to Alaqsa Mosque in Jerusalem, then Allah honored Him and took Him up with Gabriel (The Angel) to the highest heavens, and when He reached Sidrat Almuntaha (Lot-tree of the utmost boundary), He was given three things, the first of which was that the five daily prayers were made obligatory, and they were fifty, but Allah, Almighty, reduced them to five in practice and made them fifty in reward, as Abdullah bin Mas'ud narrated: "When the Messenger of Allah (PBUH) was taken for the night journey (Israa and Mi'raj), He was taken to Sidrat Almuntaha, which is situated on the sixth heaven, where terminates everything that ascends from the earth and is held there, and where terminates everything that descends from above it and is held there, he said {When covers the Sidrah what covers, Surat Alnajm Aya 16}, he said it was gold moths, he further said the Messenger of Allah was given three things, He was given five prayers, He was given the concluding verses of Surat Albaqarah, and He pardoned the grave sins for those of His Ummah who do not associate anything with Allah" (Sahih Muslim 173).
And Allah's Messenger (PBUH) has described the night journey in narration of Abu Dharr saying: "While I was at Mecca, the roof of My house was opened and Gabriel (the Angel) descended, opened My chest and washed it with Zamzam water, then He brought a golden tray full of wisdom and faith and having poured its contents into My chest, He closed it, then he took My hand and ascended with Me to the nearest heaven, when I reached the nearest heaven, Gabriel said to the gatekeeper of the heaven Open the gate, the gatekeeper asked Who is it? Gabriel answered Gabriel, he asked Is there anyone with you? Gabriel replied, yes Muhammad is with Me, He asked has He been called? Gabriel said: yes, so the gate was opened, and we went over the nearest heaven and there we saw a man sitting with some people on his right and some on his left, when He looked towards his right he laughed and when he looked towards his left He wept, then He said welcome! O pious Prophet and pious son, I asked Gabriel Who is He?, He replied He is Adam, and the people on His right and left are the souls of His offspring, those on His right are the people of Paradise and those on His left are the people of Hell, and when He looks towards His right He laughs, and when He looks towards His left He weeps.
Then He ascended with Me till He reached the second heaven, and Gabriel said to its gatekeeper Open, the gatekeeper said to Him the same as the gatekeeper of the first heaven has said, and he opened the gate, Anas said: Abu Dhar added that the Prophet met Adam, Idris, Moses, Jesus, and Abraham, He (Abu Dhar) didn't mention on which heaven they were, but He mentioned that the Prophet met Adam on the nearest heaven, and Abraham on the sixth heaven, Anas said: when Gabriel along with the Prophet (PBUH) passed by Idris, the latter said Welcome! O pious Prophet and pious brother, the Prophet asked Who is He? Gabriel replied, He is Idris.
The Prophet added, I passed by Moses and He said Welcome! O pious Prophet and pious brother, I asked Gabriel Who is He? Gabriel replied He is Moses, then I passed by Juses and He said Welcome! O pious brother and pious Prophet, I asked Who is He? Gabriel replied He is Juses, then I passed by Abraham, and He said Welcome! O pious Prophet and pious son, I asked Gabriel Who is He? Gabriel replied He is Abraham.
The prophet added, then Gabriel ascended with Me to a place where I heard the creaking of pens, Ibn Hazm and Anas bin Malik said the Prophet said, then Allah enjoined fifty prayers on My followers, when I returned with this order of Allah, I passed by Moses who asked Me, What has Allah enjoined on your followers?, I replied He has enjoined fifty prayers on them, Moses said Go back to your Lord and appeal for reduction for your followers will not be able to bear it, so I went back to Allah and requested for reduction, and He reduced it to half. When I passed by Moses again and informed Him about it He said Go back to your Lord as your followers will not be able to bear it, so I returned to Allah and requested for further reduction and half of it was reduced, I again passed by Moses, and He said to Me Return to your Lord for your followers will not be able to bear it, so I returned to Allah, and He said These are five prayers, and they are all equal to fifty in reward for My word does not change, I returned to Moses and He told Me to go back once again, I replied now I feel shy of asking My Lord again, then Gabriel took Me till we reached Sidrat Almuntaha (Lot-tree of the utmost boundary) which was shrouded in colors, indescribable, then I was admitted into paradise where I found small tents or walls made of pearls, and its earth was of musk (Sahih Albukhari 349).