Abu Dharr reported:I said: Messenger of Allah, which mosque was set up first on the earth? He said: Al-Masjid al-Haram (the sacred). I (again) said: Then which next? He said: It was the Masjid Aqsa. I (again) said: How long the space of time (between their setting up)? He (the Holy Prophet) said: It was forty years. And whenever the time comes for prayer, pray there, for that is a mosque; and in the hadith transmitted by Abu Kamil (the words are):" Whenever time comes for prayer, pray, for that is a mosque (for you)

Ibrahim b. Yazid al-Tayml reported:I used to read the Qur'an with my father in the vestibule (before the door of the mosque). When I recited the ayat (verses) concerning prostration, he prostrated himself. I said to him: Father, do you prostrate yourself in the path? He said: I heard Abu Dharr saying: I asked the Messenger of Allah (ﷺ) about the mosque that was first set up on the earth. He said: Masjid Harim. I said: Then which next? He said: The Masjid al-Aqsa. I said: How long is the space of time between the two? He said: Forty years. He (then) further said: The earth is a mosque for you, so wherever you are at the time of prayer, pray there