Al Bait-ul-Ma'mur is situated in the 7th heaven, directly above the Ka'aba on earth. The angels make hajj to this House like we make hajj to Ka'aba. The Ka'aba on earth is a replica of it.

In the 4th heaven, there is a river called Haywaan (River of Life). Each day, The leader of the angels Jibra’eel (alayhi salaam) dips in it and shakes his wings letting off seventy thousand drops. From each of these droplets Almighty Allah creates one angel.

These Angels are commanded to perform salaah in the Bait-ul-Ma’mur. Every single day 70,000 angels visit it. This will continue on until the Day of Resurrection. As soon as they perform salaah, they come out from the Bait-ul-ma’mur never to return there again.

One Angel from this group is appointed their leader and is given the duty of taking the other Angels to one spot in the Heaven where they will stand reciting the tasbeeh of Allah till the Day of Judgment.

"Nearly the heavens might be rent asunder from above them (by His Majesty): and the angels glorify the praises of their Lord, and ask for forgiveness for those on the earth. Verily, Allah is the Oft-Forgiving, the Most Merciful"
(Surah Ash-Shura:5)

"Everything in the heavens and every creature on the earth prostrates to Allah, as do the angels. They are not puffed up with pride. They fear their Lord above them and do everything they are ordered to do"
(Surah An-Nahl:49-50)

Holy Prophet PBUH said Then we ascended to the seventh heaven and again the same questions and answers were exchanged as in the previous heavens. There I met and greeted Abraham who said, 'You are welcomed O son and a Prophet.' Then I was shown Al-Bait-al-Ma'mur (i.e. Allah's House). I asked Gabriel about it and he said, This is Al Bait-ul-Ma'mur where 70,000 angels perform prayers daily and when they leave they never return to it (but always a fresh batch comes into it daily).'